Document and Entity Information - USD ($)	12 Months Ended
Document and Entity Information - USD ($)	Dec. 31, 2017	Feb. 23, 2018
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	FY
Trading Symbol	BRO
Entity Registrant Name	BROWN & BROWN, INC.
Entity Central Index Key	0000079282
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		137,800,585
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float	$ 5,014,164,392

CONDENSED CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
REVENUES
Commissions and fees	$ 1,857,270	$ 1,762,787	$ 1,656,951
Investment income	1,626	1,456	1,004
Other income, net	22,451	2,386	2,554
Total revenues	1,881,347	1,766,629	1,660,509
EXPENSES
Employee compensation and benefits	994,652	925,217	856,952
Non-cash stock-based compensation	30,631	16,052	15,513
Other operating expenses	283,470	262,872	251,055
(Gain)/loss on disposal	(2,157)	(1,291)	(619)
Amortization	85,446	86,663	87,421
Depreciation	22,698	21,003	20,890
Interest	38,316	39,481	39,248
Change in estimated acquisition earn-out payables	9,200	9,185	3,003
Total expenses	1,431,625	1,343,130	1,257,950
Income before income taxes	449,722	423,499	402,559
Income taxes	50,092	166,008	159,241
Net income	$ 399,630	$ 257,491	$ 243,318
Net income per share:
Basic (in dollars per share)	$ 2.86	$ 1.84	$ 1.72
Diluted (in dollars per share)	2.81	1.82	1.70
Dividends declared per share (in dollars per share)	$ 0.56	$ 0.50	$ 0.45

CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current Assets:
Cash and cash equivalents	$ 573,383	$ 515,646
Restricted cash and investments	250,705	265,637
Short-term investments	24,965	15,048
Premiums, commissions and fees receivable	546,402	502,482
Reinsurance recoverable	477,820	78,083
Prepaid reinsurance premiums	321,017	308,661
Other current assets	47,864	50,571
Total current assets	2,242,156	1,736,128
Fixed assets, net	77,086	75,807
Goodwill	2,716,079	2,675,402
Amortizable intangible assets, net	641,005	707,454
Investments	13,949	23,048
Other assets	57,275	44,895
Total assets	5,747,550	5,262,734
Current Liabilities:
Premiums payable to insurance companies	685,163	647,564
Losses and loss adjustment reserve	476,721	78,083
Unearned premiums	321,017	308,661
Premium deposits and credits due customers	91,648	83,765
Accounts payable	64,177	69,595
Accrued expenses and other liabilities	228,748	201,989
Current portion of long-term debt	120,000	55,500
Total current liabilities	1,987,474	1,445,157
Long-term debt less unamortized discount and debt issuance costs	856,141	1,018,372
Deferred income taxes, net	256,185	357,686
Other liabilities	65,051	81,308
Shareholders’ Equity:
Common stock, par value $0.10 per share; authorized 280,000 shares; issued 148,824 shares and outstanding 138,105 shares at 2017, issued 148,107 shares and outstanding 140,104 shares at 2016	14,882	14,811
Additional paid-in capital	497,540	468,443
Treasury stock, at cost 10,719 and 8,003 shares at 2017 and 2016, respectively	(386,322)	(257,683)
Retained earnings	2,456,599	2,134,640
Total shareholders’ equity	2,582,699	2,360,211
Total liabilities and shareholders’ equity	$ 5,747,550	$ 5,262,734

CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Short-term Investments	$ 24,965	$ 15,048
Common stock, par value (in dollars per share)	$ 0.10	$ 0.10
Common stock, shares authorized (in shares)	280,000,000	280,000,000
Common stock, shares issued (in shares)	148,823,774	148,107,038
Common Stock, Shares, Outstanding	138,105,455	140,103,841
Treasury stock shares (in shares)	10,718,319	8,003,197
Tax effect of accumulated other comprehensive income	$ 0	$ 0

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Cash Flows [Abstract]
Cash, Cash Equivalents and Restricted Cash	$ 824,088	$ 781,283	$ 673,173	$ 729,817
Cash flows from operating activities:
Net income	399,630	257,491	243,318
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization	85,446	86,663	87,421
Depreciation	22,698	21,003	20,890
Share-based Compensation	30,631	16,052	15,513
Change in estimated acquisition earn-out payables	9,200	9,185	3,003
Deferred income taxes	(102,183)	18,163	22,696
Amortization of debt discount	158	165	157
Deferred Finance Costs, Own-share Lending Arrangement, Issuance Costs, Amortization Expense	1,682	1,597	0
Accretion (Amortization) of Discounts and Premiums, Investments	22	(39)	0
Income tax benefit from exercise of shares from the stock benefit plans	0	(7,346)	(3,276)
Payments On Acquisition Earn Outs In Excess Of Original Estimated Payables	(14,501)	(3,904)	(11,383)
Loss/(gain) on sales of investments, fixed assets and customer accounts	(1,841)	596	(107)
Changes in operating assets and liabilities, net of effect from acquisitions and divestitures:
Premiums, commissions and fees receivable (increase)	(43,306)	(63,550)	(7,163)
Reinsurance recoverables (increase)	(399,737)	(46,115)	(18,940)
Prepaid reinsurance premiums (increase) decrease	(12,356)	982	10,943
Other assets (increase)	(9,747)	(4,718)	(5,318)
Premiums payable to insurance companies decrease	37,380	66,084	542
Premium deposits and credits due customers increase (decrease)	7,750	527	(2,973)
Losses and loss adjustment reserve increase	398,638	46,115	18,940
Unearned premiums increase (decrease)	12,356	(982)	(10,943)
Accounts payable increase	26,798	30,174	34,206
Accrued expenses and other liabilities increase	25,509	8,670	8,204
Other liabilities (decrease)	(32,252)	(25,849)	(23,898)
Net cash provided by operating activities	441,975	411,042	381,832
Cash flows from investing activities:
Additions to fixed assets	(24,192)	(17,765)	(18,375)
Payments for businesses acquired, net of cash acquired	(41,471)	(122,622)	(136,000)
Proceeds from sales of fixed assets and customer accounts	4,094	4,957	10,576
Purchases of investments	(10,665)	(25,872)	(22,766)
Proceeds from Sale, Maturity and Collection of Investments	9,644	18,890	21,928
Net cash used in investing activities	(62,590)	(142,412)	(144,637)
Cash flows from financing activities:
Payments on acquisition earn-outs	(29,265)	(24,309)	(25,415)
Payments on long-term debt	(96,750)	(73,125)	(45,625)
Income tax benefit from exercise of shares from the stock benefit plans	0	7,346	3,276
Issuances of common stock for employee stock benefit plans	17,422	15,983	15,890
Repurchase of stock benefit plan shares for employees to fund tax withholdings	(7,565)	(8,495)	(2,857)
Purchase of treasury stock	(128,639)	(18,908)	(163,750)
Settlement (prepayment) of accelerated share repurchase program	(11,250)	11,250	11,250
Cash dividends paid	(77,712)	(70,262)	(64,108)
Net cash used in by financing activities	(336,580)	(160,520)	(293,839)
Payments of Debt Issuance Costs	(2,821)
Net increase (decrease) in cash and cash equivalents inclusive of restricted cash	$ 42,805	$ 108,110	$ (56,644)

Shareholders Equity Statement - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Retained Earnings [Member]
Common Stock, Shares, Outstanding		145,871
Stockholders' Equity Attributable to Parent at Dec. 31, 2014	$ 2,113,745	$ 14,587	$ 405,982	$ (75,025)	$ 1,768,201
Common Stock Issued to Directors	500,000	2,000	498,000
Dividends, Cash	$ (64,108)				(64,108)
Net Income (Loss) Attributable to Parent	243,318				243,318
Stock Issued During Period, Value, Employee Benefit Plan		528
Stock Issued During Period, Value, Employee Benefit Plan	28,045	$ 53	$ 27,992
Treasury Stock, Value, Acquired, Cost Method	(175,000)		(11,250)	(163,750)
Adjustment to Additional Paid in Capital, Income Tax Effect from Share-based Compensation, Net	3,276		3,276
Common Stock Issued to Directors Shares		16
Stockholders' Equity Attributable to Parent at Dec. 31, 2015	$ 2,149,776	$ 14,642	$ 426,498	(238,775)	1,947,411
Common Stock, Shares, Outstanding		146,415
Common Stock Issued to Directors	500,000	2,000	498,000
Dividends, Cash	$ (70,262)				(70,262)
Net Income (Loss) Attributable to Parent	257,491				257,491
Stock Issued During Period, Value, Employee Benefit Plan		1,675
Stock Issued During Period, Value, Employee Benefit Plan	23,018	$ 167	$ 22,851
Treasury Stock, Value, Acquired, Cost Method	(7,658)		11,250	(18,908)
Adjustment to Additional Paid in Capital, Income Tax Effect from Share-based Compensation, Net	7,346		7,346
Common Stock Issued to Directors Shares		17
Stockholders' Equity Attributable to Parent at Dec. 31, 2016	$ 2,360,211	$ 14,811	$ 468,443	(257,683)	2,134,640
Common Stock, Shares, Outstanding	140,103,841	148,107
Net Unrealized Holding Gain on Available for Sale Securities	$ (12)
Common Stock Issued to Directors	500,000	1,000	499,000
Dividends, Cash	$ (77,712)				(77,712)
Net Income (Loss) Attributable to Parent	399,630				399,630
Stock Issued During Period, Value, Employee Benefit Plan		706
Stock Issued During Period, Value, Employee Benefit Plan	39,965	$ 70	$ 39,895
Treasury Stock, Value, Acquired, Cost Method	(139,889)		(11,250)	(128,639)
Common Stock Issued to Directors Shares		11
Stockholders' Equity Attributable to Parent at Dec. 31, 2017	$ 2,582,699	$ 14,882	497,540	$ (386,322)	2,456,599
Common Stock, Shares, Outstanding	138,105,455	148,824
Net Unrealized Holding Gain on Available for Sale Securities	$ (6)		$ (47)		$ 41

Net Income Per Share

12 Months Ended

Dec. 31, 2017

Earnings Per Share [Abstract]

Net Income Per Share

Basic EPS is computed based upon the weighted-average number of common shares (including participating securities) issued and outstanding during the period. Diluted EPS is computed based upon the weighted-average number of common shares issued and outstanding plus equivalent shares, assuming the exercise of stock options. The dilutive effect of stock options is computed by application of the treasury-stock method. The following is a reconciliation between basic and diluted weighted-average shares outstanding for the years ended December 31:



(in thousands, except per share data)	2017			2016			2015
Net income	$	399,630		$	257,491		$	243,318
Net income attributable to unvested awarded performance stock	(9,746		)	(6,705		)	(5,695		)
Net income attributable to common shares	$	389,884		$	250,786		$	237,623
Weighted-average number of common shares outstanding – basic	139,697			139,779			141,113
Less unvested awarded performance stock included in weighted-average number of common shares outstanding – basic	(3,407		)	(3,640		)	(3,303		)
Weighted-average number of common shares outstanding for basic earnings per common share	136,290			136,139			137,810
Dilutive effect of stock options	2,503			1,665			2,302
Weighted-average number of shares outstanding – diluted	138,793			137,804			140,112
Net income per share:
Basic	$	2.86		$	1.84		$	1.72
Diluted	$	2.81		$	1.82		$	1.70

Business Combinations

12 Months Ended

Dec. 31, 2017

Business Combinations [Abstract]

Business Combinations

During the year ended December 31, 2017, the Company acquired the assets and assumed certain liabilities of eleven insurance intermediaries and one book of business (customer accounts). Additionally, miscellaneous adjustments were recorded to the purchase price allocation of certain prior acquisitions completed within the last twelve months as permitted by Accounting Standards Codification Topic 805 - Business Combinations (“ASC 805”). Such adjustments are presented in the “Other” category within the following two tables. All of these businesses were acquired primarily to expand Brown & Brown’s core business and to attract and hire high-quality individuals. The recorded purchase price for all acquisitions consummated after January 1, 2009 included an estimation of the fair value of liabilities associated with any potential earn-out provisions. Subsequent changes in the fair value of earn-out obligations will be recorded in the Consolidated Statement of Income when incurred.

The fair value of earn-out obligations is based upon the present value of the expected future payments to be made to the sellers of the acquired businesses in accordance with the provisions outlined in the respective purchase agreements. In determining fair value, the acquired business’s future performance is estimated using financial projections developed by management for the acquired business and reflects market participant assumptions regarding revenue growth and/or profitability. The expected future payments are estimated on the basis of the earn-out formula and performance targets specified in each purchase agreement compared to the associated financial projections. These payments are

then discounted to present value using a risk-adjusted rate that takes into consideration the likelihood that the forecasted earn-out payments will be made.

Based upon the acquisition date and the complexity of the underlying valuation work, certain amounts included in the Company’s Consolidated Financial Statements may be provisional and thus subject to further adjustments within the permitted measurement period, as defined in ASC 805. For the year ended December 31, 2017, several adjustments were made within the permitted measurement period that resulted in an increase in the aggregate purchase price of the affected acquisitions of $1.5 million relating to the assumption of certain liabilities. These measurement period adjustments have been reflected as current period adjustments for the year ended December 31, 2017 in accordance with the guidance in ASU 2015-16 “Business Combinations.” The measurement period adjustments impacted goodwill, with no effect on earnings or cash in the current period.

Cash paid for acquisitions was $41.5 million and $124.7 million in the years ended December 31, 2017 and 2016, respectively. We completed eleven acquisitions (excluding book of business purchases) during the year ended December 31, 2017. We completed eight acquisitions (excluding book of business purchases) during the year ended December 31, 2016.

The following table summarizes the purchase price allocation made as of the date of each acquisition for current year acquisitions and significant adjustments made during the measurement period for prior year acquisitions. During the measurement periods, the Company will adjust assets or liabilities if new information is obtained about facts and circumstances that existed as of the acquisition date that, if known, would have resulted in the recognition of those assets and liabilities as of that date. These adjustments are made in the period in which the amounts are determined and the current period income effect of such adjustments will be calculated as if the adjustments had been completed as of the acquisition date.



(in thousands)
Name	Business Segment	Effective Date of Acquisition	Cash Paid		Other Payable		Recorded Earn-Out Payable		Net Assets Acquired		Maximum Potential Earn- Out Payable
Other	Various	Various	$	41,471	$	11,708	$	6,921	$	60,100	$	27,451
Total			$	41,471	$	11,708	$	6,921	$	60,100	$	27,451

The following table summarizes the estimated fair values of the aggregate assets and liabilities acquired as of the date of each acquisition.



(in thousands)	Total
Other current assets	$	601
Fixed assets	69
Goodwill	42,172
Purchased customer accounts	18,738
Non-compete agreements	721
Total assets acquired	62,301
Other current liabilities	(1,512		)
Deferred income tax, net	(689		)
Total liabilities assumed	(2,201		)
Net assets acquired	$	60,100

The weighted-average useful lives for the acquired amortizable intangible assets are as follows: purchased customer accounts, 15.0 years; and non-compete agreements, 5.0 years.

Goodwill of $42.2 million was allocated to the Retail, National Programs, Wholesale Brokerage and Services Segments in the amounts of $33.1 million, $7.2 million, $1.2 million and $0.7 million, respectively. Of the total goodwill of $42.2 million, $35.3 million is currently deductible for income tax purposes. The remaining $6.9 million relates to the recorded earn-out payables and will not be deductible until it is earned and paid.

For the acquisitions completed during 2017, the results of operations since the acquisition dates have been combined with those of the Company. The total revenues from the acquisitions completed through December 31, 2017 included in the Consolidated Statement of Income for the year ended December 31, 2017 were $7.8 million. The income before income taxes, including the intercompany cost of capital charge, from the acquisitions completed through December 31, 2017 included in the Consolidated Statement of Income for the year ended December 31, 2017 was $2.4 million. If the acquisitions had occurred as of the beginning of the respective periods, the Company’s results of operations would be as shown in the following table. These unaudited pro forma results are not necessarily indicative of the actual results of operations that would have occurred had the acquisitions actually been made at the beginning of the respective periods.



(UNAUDITED)	For the Year Ended December 31,
(in thousands, except per share data)	2017		2016
Total revenues	$	1,891,701	$	1,784,776
Income before income taxes	$	453,397	$	429,490
Net income	$	401,908	$	261,133
Net income per share:
Basic	$	2.88	$	1.87
Diluted	$	2.83	$	1.85
Weighted-average number of shares outstanding:
Basic	136,290		136,139
Diluted	138,793		137,804

Acquisitions in 2016

During the year ended December 31, 2016, the Company acquired the assets and assumed certain liabilities of seven insurance intermediaries, all of the stock of one insurance intermediary and three books of business (customer accounts). Additionally, miscellaneous adjustments were recorded to the purchase price allocation of certain prior acquisitions completed within the last twelve months as permitted by ASC 805. Such adjustments are presented in the “Other” category within the following two tables.

For the year ended December 31, 2016, several adjustments were made within the permitted measurement period that resulted in a decrease in the aggregate purchase price of the affected acquisitions of $917,497, relating to the assumption of certain liabilities.



(in thousands)
Name	Business Segment	Effective Date of Acquisition	Cash Paid		Note Payable		Other Payable		Recorded Earn-Out Payable		Net Assets Acquired		Maximum Potential Earn- Out Payable
Social Security Advocates for the Disabled LLC (SSAD)	Services	February 1, 2016	$	32,526	$	492	$	—	$	971	$	33,989	$	3,500
Morstan General Agency, Inc. (Morstan)	Wholesale Brokerage	June 1, 2016	66,050		—		10,200		3,091		79,341		5,000
Other	Various	Various	26,140		—		464		400		27,004		7,785
Total			$	124,716	$	492	$	10,664	$	4,462	$	140,334	$	16,285

The following table summarizes the estimated fair values of the aggregate assets and liabilities acquired as of the date of each acquisition.



(in thousands)	SSAD			Morstan			Other			Total
Cash	$	2,094		$	—		$	—		$	2,094
Other current assets	1,042			2,482			1,555			5,079
Fixed assets	307			300			77			684
Goodwill	22,352			51,454			19,570			93,376
Purchased customer accounts	13,069			26,481			11,075			50,625
Non-compete agreements	72			39			117			228
Other assets	—			—			20			20
Total assets acquired	38,936			80,756			32,414			152,106
Other current liabilities	(1,717		)	(1,415		)	(5,410		)	(8,542		)
Deferred income tax, net	(3,230		)	—			—			(3,230		)
Total liabilities assumed	(4,947		)	(1,415		)	(5,410		)	(11,772		)
Net assets acquired	$	33,989		$	79,341		$	27,004		$	140,334

The weighted-average useful lives for the acquired amortizable intangible assets are as follows: purchased customer accounts, 15 years; and non-compete agreements, 5 years.

Goodwill of $93.4 million was allocated to the Retail, National Programs, Wholesale Brokerage and Services Segments in the amounts of $13.1 million, $(1.2) thousand, $57.9 million and $22.4 million, respectively. Of the total goodwill of $93.4 million, $88.9 million is currently deductible for income tax purposes. The remaining $4.5 million relates to the recorded earn-out payables and will not be deductible until it is earned and paid.

For the acquisitions completed during 2016, the results of operations since the acquisition dates have been combined with those of the Company. The total revenues from the acquisitions completed through December 31, 2016 included in the Consolidated Statement of Income for the year ended December 31, 2016 were $34.2 million. The income before income taxes, including the intercompany cost of capital charge, from the acquisitions completed through December 31, 2016 included in the Consolidated Statement of Income for the year ended December 31, 2016 was $4.3 million. If the acquisitions had occurred as of the beginning of the respective periods, the Company’s results of operations would be as shown in the following table. These unaudited pro forma results are not necessarily indicative of the actual results of operations that would have occurred had the acquisitions actually been made at the beginning of the respective periods.



(UNAUDITED)	For the Year Ended December 31,
(in thousands, except per share data)	2016		2015
Total revenues	$	1,789,790	$	1,716,592
Income before income taxes	$	428,194	$	414,911
Net income	$	260,346	$	250,783
Net income per share:
Basic	$	1.86	$	1.78
Diluted	$	1.84	$	1.75
Weighted-average number of shares outstanding:
Basic	136,139		137,810
Diluted	137,804		140,112

Acquisitions in 2015

During the year ended December 31, 2015, Brown & Brown acquired the assets and assumed certain liabilities of thirteen insurance intermediaries and four books of business (customer accounts). The cash paid for these acquisitions was $136.0 million. Additionally, miscellaneous adjustments were recorded to the purchase price allocation of certain prior acquisitions completed within the last twelve months as permitted by ASC 805. Such adjustments are presented in “Other” within the following two tables. All of these businesses were acquired primarily to expand Brown & Brown’s core business and to attract and hire high-quality individuals.

For the year ended December 31, 2015, several adjustments were made within the permitted measurement period that resulted in a decrease in the aggregate purchase price of the affected acquisitions of $503,442 relating to the assumption of certain liabilities.



(in thousands)
Name	Business Segment	Effective Date of Acquisition	Cash Paid		Other Payable		Recorded Earn-Out Payable		Net Assets Acquired		Maximum Potential Earn- Out Payable
Liberty Insurance Brokers, Inc. and Affiliates (Liberty)	Retail	February 1, 2015	$	12,000	$	—	$	2,981	$	14,981	$	3,750
Spain Agency, Inc. (Spain)	Retail	March 1, 2015	20,706		—		2,617		23,323		9,162
Bellingham Underwriters, Inc. (Bellingham)	National Programs	May 1, 2015	9,007		500		3,322		12,829		4,400
Fitness Insurance, LLC (Fitness)	Retail	June 1, 2015	9,455		—		2,379		11,834		3,500
Strategic Benefit Advisors, Inc. (SBA)	Retail	June 1, 2015	49,600		400		13,587		63,587		26,000
Bentrust Financial, Inc. (Bentrust)	Retail	December 1, 2015	10,142		391		319		10,852		2,200
MBA Insurance Agency of Arizona, Inc. (MBA)	Retail	December 1, 2015	68		8,442		6,063		14,573		9,500
Smith Insurance, Inc. (Smith)	Retail	December 1, 2015	12,096		200		1,047		13,343		6,350
Other	Various	Various	12,926		95		4,584		17,605		8,212
Total			$	136,000	$	10,028	$	36,899	$	182,927	$	73,074

The following table summarizes the estimated fair values of the aggregate assets and liabilities acquired as of the date of each acquisition. The data included in the “Other” column shows a negative adjustment for purchased customer accounts. This is driven mainly by the final valuation adjustment for the acquisition of Wright.



(in thousands)	Liberty			Spain			Bellingham			Fitness			SBA		Bentrust			MBA			Smith			Other			Total
Other current assets	$	2,486		$	324		$	—		$	9		$	652	$	—		$	—		$	—		$	169		$	3,640
Fixed assets	40			50			25			17			41		36			33			73			59			374
Goodwill	10,010			15,748			9,608			8,105			39,859		8,166			13,471			10,374			21,040			136,381
Purchased customer accounts	4,506			7,430			3,223			3,715			23,000		2,789			7,338			3,526			(2,135		)	53,392
Non-compete agreements	24			21			21			—			21		43			11			31			156			328
Other assets	—			—			—			—			14		—			—			—			—			14
Total assets acquired	17,066			23,573			12,877			11,846			63,587		11,034			20,853			14,004			19,289			194,129
Other current liabilities	(42		)	(250		)	(48		)	(12		)	—		(182		)	(6,280		)	(504		)	(4,895		)	(12,213		)
Deferred income tax, net	—			—			—			—			—		—			—			—			2,576			2,576
Other liabilities	(2,043		)	—			—			—			—		—			—			(157		)	635			(1,565		)
Total liabilities assumed	(2,085		)	(250		)	(48		)	(12		)	—		(182		)	(6,280		)	(661		)	(1,684		)	(11,202		)
Net assets acquired	$	14,981		$	23,323		$	12,829		$	11,834		$	63,587	$	10,852		$	14,573		$	13,343		$	17,605		$	182,927

The weighted-average useful lives for the acquired amortizable intangible assets are as follows: purchased customer accounts, 15 years; and non-compete agreements, 5 years.

Goodwill of $136.4 million was allocated to the Retail, National Programs and Wholesale Brokerage Segments in the amounts of $113.8 million, $18.0 million and $4.6 million, respectively. Of the total goodwill of $136.4 million, $91.1 million is currently deductible for income tax purposes and $8.4 million is non-deductible. The remaining $36.9 million relates to the recorded earn-out payables and will not be deductible until it is earned and paid.

For the acquisitions completed during 2015, the results of operations since the acquisition dates have been combined with those of the Company. The total revenues from the acquisitions completed through December 31, 2015, included in the Consolidated Statement of Income for the year ended December 31, 2015, were $28.2 million. The income before income taxes, including the intercompany cost of capital charge, from the acquisitions completed through December 31, 2015, included in the Consolidated Statement of Income for the year ended December 31, 2015, was $1.5 million. If the acquisitions had occurred as of the beginning of the respective periods, the Company’s results of operations would be as shown in the following table. These unaudited pro forma results are not necessarily indicative of the actual results of operations that would have occurred had the acquisitions actually been made at the beginning of the respective periods.



(UNAUDITED)	For the Year Ended December 31,
(in thousands, except per share data)	2015
Total revenues	$	1,688,297
Income before income taxes	$	411,497
Net income	$	248,720
Net income per share:
Basic	$	1.76
Diluted	$	1.73
Weighted-average number of shares outstanding:
Basic	137,810
Diluted	140,112

As of December 31, 2017, the maximum future contingency payments related to all acquisitions totaled $88.4 million, all of which relates to acquisitions consummated subsequent to January 1, 2009.

ASC 805 is the authoritative guidance requiring an acquirer to recognize 100% of the fair values of acquired assets, including goodwill, and assumed liabilities (with only limited exceptions) upon initially obtaining control of an acquired entity. Additionally, the fair value of contingent consideration arrangements (such as earn-out purchase arrangements) at the acquisition date must be included in the purchase price consideration. As a result, the recorded purchase prices for all acquisitions consummated after January 1, 2009 include an estimation of the fair value of liabilities associated with any potential earn-out provisions. Subsequent changes in these earn-out obligations will be recorded in the Consolidated Statement of Income when incurred. Potential earn-out obligations are typically based upon future earnings of the acquired entities, usually between one and three years.

As of December 31, 2017, the fair values of the estimated acquisition earn-out payables were re-evaluated and measured at fair value on a recurring basis using unobservable inputs (Level 3) as defined in ASC 820-Fair Value Measurement. The resulting additions, payments and net changes, as well as the interest expense accretion on the estimated acquisition earn-out payables, for the years ended December 31, 2017, 2016 and 2015 were as follows:



	For the Year Ended December 31,
(in thousands)	2017			2016			2015
Balance as of the beginning of the period	$	63,821		$	78,387		$	75,283
Additions to estimated acquisition earn-out payables	6,920			4,462			36,899
Payments for estimated acquisition earn-out payables	(43,766		)	(28,213		)	(36,798		)
Subtotal	26,975			54,636			75,384
Net change in earnings from estimated acquisition earn-out payables:
Change in fair value on estimated acquisition earn-out payables	6,874			6,338			13
Interest expense accretion	2,326			2,847			2,990
Net change in earnings from estimated acquisition earn-out payables	9,200			9,185			3,003
Balance as of December 31,	$	36,175		$	63,821		$	78,387

Of the $36.2 million of estimated acquisition earn-out payables as of December 31, 2017, $25.1 million was recorded as accounts payable, and $11.1 million was recorded as other non-current liabilities. Included within additions to estimated acquisition earn-out payables are any adjustments to opening balance sheet items prior to the one-year anniversary date of the acquisition and may therefore differ from previously reported amounts. Of the $63.8 million of estimated acquisition earn-out payables as of December 31, 2016, $31.8 million was

recorded as accounts payable, and $32.0 million was recorded as other non-current liabilities. Of the $78.4 million of estimated acquisition earn-out payables as of December 31, 2015, $25.3 million was recorded as accounts payable, and $53.1 million was recorded as another non-current liability.

- Definition

The entire disclosure for a business combination (or series of individually immaterial business combinations) completed during the period, including background, timing, and recognized assets and liabilities. The disclosure may include leverage buyout transactions (as applicable).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
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+ Details

Goodwill

12 Months Ended

Dec. 31, 2017

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill

The changes in the carrying value of goodwill by reportable segment for the years ended December 31, are as follows:



(in thousands)	Retail			National Programs			Wholesale Brokerage		Services		Total
Balance as of January 1, 2016	$	1,345,636		$	901,866		$	226,961	$	112,220	$	2,586,683
Goodwill of acquired businesses	13,117			(1		)	57,908		22,352		93,376
Goodwill of transferred businesses	571			(571		)	—		—		—
Goodwill disposed of relating to sales of businesses	(4,657		)	—			—		—		(4,657		)
Balance as of December 31, 2016	$	1,354,667		$	901,294		$	284,869	$	134,572	$	2,675,402
Goodwill of acquired businesses	33,076			7,178			1,229		689		42,172
Goodwill disposed of relating to sales of businesses	(1,495		)	—			—		—		(1,495		)
Balance as of December 31, 2017	$	1,386,248		$	908,472		$	286,098	$	135,261	$	2,716,079

- Definition

The entire disclosure for the aggregate amount of goodwill and a description of intangible assets, which may include (a) for amortizable intangible assets (also referred to as finite-lived intangible assets), the carrying amount, the amount of any significant residual value, and the weighted-average amortization period, (b) for intangible assets not subject to amortization (also referred to as indefinite-lived intangible assets), the carrying amount, and (c) the amount of research and development assets acquired and written off in the period, including the line item in the income statement in which the amounts written off are aggregated, if not readily apparent from the income statement. Also discloses (a) for amortizable intangibles assets in total and by major class, the gross carrying amount and accumulated amortization, the total amortization expense for the period, and the estimated aggregate amortization expense for each of the five succeeding fiscal years, (b) for intangible assets not subject to amortization the carrying amount in total and by major class, and (c) for goodwill, in total and for each reportable segment, the changes in the carrying amount of goodwill during the period (including the aggregate amount of goodwill acquired, the aggregate amount of impairment losses recognized, and the amount of goodwill included in the gain (loss) on disposal of a reporting unit). If any part of goodwill has not been allocated to a reportable segment, discloses the unallocated amount and the reasons for not allocating. For each impairment loss recognized related to an intangible asset (excluding goodwill), discloses: (a) a description of the impaired intangible asset and the facts and circumstances leading to the impairment, (b) the amount of the impairment loss and the method for determining fair value, (c) the caption in the income statement or the statement of activities in which the impairment loss is aggregated, and (d) the segment in which the impaired intangible asset is reported. For each goodwill impairment loss recognized, discloses: (a) a description of the facts and circumstances leading to the impairment, (b) the amount of the impairment loss and the method of determining the fair value of the associated reporting unit, and (c) if a recognized impairment loss is an estimate not finalized and the reasons why the estimate is not final. May also disclose the nature and amount of any significant adjustments made to a previous estimate of an impairment loss.

+ References + Details

Amortizable Intangible Assets

12 Months Ended

Dec. 31, 2017

Goodwill and Intangible Assets Disclosure [Abstract]

Amortizable Intangible Assets

Amortizable intangible assets at December 31, 2017 and 2016 consisted of the following:



	December 31, 2017								December 31, 2016
(in thousands)	Gross Carrying Value		Accumulated Amortization			Net Carrying Value		Weighted Average Life in Years⁽¹⁾	Gross Carrying Value		Accumulated Amortization			Net Carrying Value		Weighted Average Life in Years⁽¹⁾
Purchased customer accounts	$	1,464,274	$	(824,584	)	$	639,690	15.0	$	1,447,680	$	(741,770	)	$	705,910	15.0
Non-compete agreements	30,287		(28,972		)	1,315		6.8	29,668		(28,124		)	1,544		6.8
Total	$	1,494,561	$	(853,556	)	$	641,005		$	1,477,348	$	(769,894	)	$	707,454


(1)	Weighted-average life calculated as of the date of acquisition.

Amortization expense for amortizable intangible assets for the years ending December 31, 2018, 2019, 2020, 2021 and 2022 is estimated to be $81.0 million, $76.5 million, $69.1 million, $65.9 million and $61.4 million, respectively.

Investments

12 Months Ended

Dec. 31, 2017

Investments, Debt and Equity Securities [Abstract]

Investments

At December 31, 2017, the Company’s amortized cost and fair values of fixed maturity securities are summarized as follows:



(in thousands)	Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
U.S. Treasury securities, obligations of U.S. Government agencies and Municipalities	$	29,970	$	—	$	(206	)	$	29,764
Corporate debt	1,072		12		—			1,084
Total	$	31,042	$	12	$	(206	)	$	30,848

At December 31, 2017, the Company held $30.0 million in fixed income securities composed of U.S Treasury securities, securities issued by U.S. Government agencies and Municipalities, and $1.1 million issued by corporations with investment-grade ratings. Of the total, $16.9 million is classified as short-term investments on the Consolidated Balance Sheet as maturities are less than one year in duration. Additionally, the Company holds $8.1 million in short-term investments, which are related to time deposits held with various financial institutions.

For securities in a loss position, the following table shows the investments’ gross unrealized loss and fair value, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position as of December 31, 2017:



(in thousands)	Less than 12 Months					12 Months or More					Total
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
U.S. Treasury securities, obligations of U.S. Government agencies and Municipalities	$	17,919	$	(157	)	$	11,845	$	(49	)	$	29,764	$	(206	)
Corporate debt	400		—			—		—			400		—
Total	$	18,319	$	(157	)	$	11,845	$	(49	)	$	30,164	$	(206	)

The unrealized losses from corporate issuers were caused by interest rate increases. At December 31, 2017, the Company had 27 securities in an unrealized loss position. The corporate securities are highly rated securities with no indicators of potential impairment. Based upon the ability and intent of the Company to hold these investments until recovery of fair value, which may be maturity, the bonds were not considered to be other-than-temporarily impaired at December 31, 2017.

At December 31, 2016, the Company’s amortized cost and fair values of fixed maturity securities are summarized as follows:



(in thousands)	Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
U.S. Treasury securities, obligations of U.S. Government agencies and Municipalities	$	26,280	$	11	$	(59	)	$	26,232
Corporate debt	2,358		13		(1		)	2,370
Total	$	28,638	$	24	$	(60	)	$	28,602

The following table shows the investments’ gross unrealized loss and fair value, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position as of December 31, 2016:



(in thousands)	Less than 12 Months					12 Months or More				Total
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
U.S. Treasury securities, obligations of U.S. Government agencies and Municipalities	$	14,663	$	(59	)	$	—	$	—	$	14,663	$	(59	)
Corporate debt	1,001		(1		)	—		—		1,001		(1		)
Total	$	15,664	$	(60	)	$	—	$	—	$	15,664	$	(60	)

The unrealized losses in the Company’s investments in U.S. Treasury Securities and obligations of U.S. Government Agencies and bonds from corporate issuers were caused by interest rate increases. At December 31, 2016, the Company had 20 securities in an unrealized loss position. The contractual cash flows of the U.S. Treasury Securities and obligations of the U.S. Government agencies investments are either guaranteed by the U.S. Government or an agency of the U.S. Government. Accordingly, it is expected that the securities would not be settled at a price less than the amortized cost of the Company’s investment. The corporate securities are highly rated securities with no indicators of potential impairment. Based upon the ability and intent of the Company to hold these investments until recovery of fair value, which may be maturity, the bonds were not considered to be other-than-temporarily impaired at December 31, 2016.

The amortized cost and estimated fair value of the fixed maturity securities at December 31, 2017 by contractual maturity are set forth below:



(in thousands)	Amortized Cost		Fair Value
Years to maturity:
Due in one year or less	$	16,934	$	16,899
Due after one year through five years	13,876		13,708
Due after five years through ten years	232		241
Total	$	31,042	$	30,848

The amortized cost and estimated fair value of the fixed maturity securities at December 31, 2016 by contractual maturity are set forth below:



(in thousands)	Amortized Cost		Fair Value
Years to maturity:
Due in one year or less	$	5,551	$	5,554
Due after one year through five years	22,757		22,708
Due after five years through ten years	330		340
Total	$	28,638	$	28,602

The expected maturities in the foregoing table may differ from the contractual maturities because certain borrowers have the right to call or prepay obligations with or without penalty.

Proceeds from the sales and maturity of the Company’s investment in fixed maturity securities were $5.8 million. This along with maturing time deposits yielded total cash proceeds from the sale of investments of $9.6 million in the period of January 1, 2017 to December 31, 2017. These proceeds were used to purchase additional fixed maturity securities. The gains and losses realized on those sales for the period from January 1, 2017 to December 31, 2017 were insignificant.

Proceeds from the sales and maturity of the Company’s investment in fixed maturity securities were $6.0 million for the year ended December 31, 2016. This along with maturing time deposits and the utilization of funds from a money market account of $9.1 million yielded total cash proceeds from the sale of investments of $18.9 million in the period of January 1, 2016 to December 31, 2016. These proceeds were used to purchase additional fixed- maturity securities. The gains and losses realized on those sales for the period from January 1, 2016 to December 31, 2016 were insignificant. Additionally, there was a sale of the short-duration fixed income fund which resulted in cash proceeds of $1.7 million, as the fund was liquidated in the third quarter of 2016. Gains on this sale were also insignificant.

Realized gains and losses are reported on the Consolidated Statement of Income, with the cost of securities sold determined on a specific identification basis.

At December 31, 2017, investments with a fair value of approximately $4.1 million were on deposit with state insurance departments to satisfy regulatory requirements.

- Definition

The entire disclosure for investments in certain debt and equity securities.

+ References + Details

Fixed Assets (Notes)

12 Months Ended

Dec. 31, 2017

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment Disclosure [Text Block]

Fixed Assets

Fixed assets at December 31 consisted of the following:



(in thousands)	2017			2016
Furniture, fixtures and equipment	$	190,784		$	177,823
Leasehold improvements	35,481			33,137
Land, buildings and improvements	7,643			3,375
Total cost	233,908			214,335
Less accumulated depreciation and amortization	(156,822		)	(138,528		)
Total	$	77,086		$	75,807

Depreciation and amortization expense for fixed assets amounted to $22.7 million in 2017, $21.0 million in 2016 and $20.9 million in 2015.

Long-Term Debt

12 Months Ended

Dec. 31, 2017

Debt Disclosure [Abstract]

Long-Term Debt

Long-term debt at December 31, 2017 and 2016 consisted of the following:



(in thousands)	December 31, 2017			December 31, 2016
Current portion of long-term debt:
Current portion of 5-year term loan facility expires 2019	$	20,000		$	55,000
4.500% senior notes, Series E, quarterly interest payments, balloon due 2018	100,000			—
Short-term promissory note	—			500
Total current portion of long-term debt	120,000			55,500
Long-term debt:
Note agreements:
4.500% senior notes, Series E, quarterly interest payments, balloon due 2018	—			100,000
4.200% senior notes, semi-annual interest payments, balloon due 2024	498,943			498,785
Total notes	498,943			598,785
Credit agreements:
5-year term loan facility, periodic interest and principal payments, LIBOR plus up to 1.750%, expires June 28, 2022	365,000			426,250
5-year revolving loan facility, periodic interest payments, currently LIBOR plus up to 1.500%, plus commitment fees up to 0.250%, expires June 28, 2022	—			—
Total credit agreements	365,000			426,250
Debt issuance costs (contra)	(7,802		)	(6,663		)
Total long-term debt less unamortized discount and debt issuance costs	856,141			1,018,372
Current portion of long-term debt	120,000			55,500
Total debt	$	976,141		$	1,073,872

On December 22, 2006, the Company entered into a Master Shelf and Note Purchase Agreement (the “Master Agreement”) with a national insurance company (the “Purchaser”). The initial issuance of notes under the Master Agreement occurred on December 22, 2006, through the issuance of $25.0 million in Series C Senior Notes due December 22, 2016, with a fixed interest rate of 5.660% per year. On February 1, 2008, $25.0 million in Series D Senior Notes due January 15, 2015, with a fixed interest rate of 5.370% per year, were issued. On September 15, 2011, and pursuant to a Confirmation of Acceptance (the “Confirmation”), dated January 21, 2011, in connection with the Master Agreement, $100.0 million in Series E Senior Notes were issued and are due September 15, 2018, with a fixed interest rate of 4.500% per year. The Series E Senior Notes were issued for the sole purpose of retiring existing senior notes. On January 15, 2015, the Series D Notes were redeemed at maturity using cash proceeds to pay off the principal of $25.0 million plus any remaining accrued interest. On December 22, 2016, the Series C Notes were redeemed at maturity using cash proceeds to pay off the principal of $25.0 million plus any remaining accrued interest. As of December 31, 2017, there was an outstanding debt balance issued under the provisions of the Master Agreement of $100.0 million.

On April 17, 2014, the Company entered into a credit agreement with JPMorgan Chase Bank, N.A. as administrative agent and certain other banks as co-syndication agents and co-documentation agents (the “Credit Agreement”). The Credit Agreement in the amount of $1,350.0 million provides for an unsecured revolving credit facility (the “Credit Facility”) in the initial amount of $800.0 million and unsecured term loans in the initial amount of $550.0 million, either or both of which may, subject to lenders’ discretion, potentially be increased by up to $500.0 million. The Credit Facility was funded on May 20, 2014 in conjunction with the closing of the Wright acquisition, with the $550.0 million term loan being funded as well as a drawdown of $375.0 million on the revolving loan facility. Use of these proceeds was to retire existing term loan debt and to facilitate the closing of the Wright acquisition as well as other acquisitions. The Credit Facility terminates on May 20, 2019, but either or both of the revolving credit facility and the term loans may be extended for two additional one year periods at the Company’s request and at the discretion of the respective lenders. Interest and facility fees in respect to the Credit Facility are based upon the better of the Company’s net debt leverage ratio or a non-credit enhanced senior unsecured long-term debt rating. Based upon the Company’s net debt leverage ratio, the rates of interest charged on the term loan are 1.000% to 1.750%, and the revolving loan is 0.850% to 1.500% above the adjusted LIBOR rate for outstanding amounts drawn. There are fees included in the facility which include a facility fee based upon the revolving credit commitments of the lenders (whether used or unused) at a rate of 0.150% to 0.250% and letter of credit fees based upon the amounts of outstanding secured or unsecured letters of credit. The Credit Facility includes various covenants, limitations and events of default customary for similar facilities for similarly rated borrowers.

On June 28, 2017, the Company entered into an amended and restated credit agreement (the “Amended and Restated Credit Agreement”) with the lenders named therein, JPMorgan Chase Bank, N.A. as administrative agent and certain other banks as co-syndication agents and co-documentation agents. The Amended and Restated Credit Agreement amended and restated the credit agreement dated April 17, 2014, among such parties (the “Original Credit Agreement”). The Amended and Restated Credit Agreement extends the applicable maturity date of the existing revolving credit facility (the “Facility”) of $800.0 million to June 28, 2022 and re-evidences unsecured term loans at $400.0 million, while also extending the applicable maturity date to June 28, 2022. The quarterly term loan principal amortization schedule was reset. At the time of the execution of the Amended and Restated Credit Agreement, $67.5 million of principal from the original unsecured term loans was repaid using operating cash balances, and the Company added an additional $2.8 million in debt issuance costs related to the Facility to the Consolidated Balance Sheet. The Company also expensed to the Consolidated Statements of Income $0.2 million of debt issuance costs related to the Original Credit Agreement due to certain lenders exiting prior to execution of the Amended and Restated Credit Agreement. The Company also carried forward $1.6 million on the Consolidated Balance Sheet the remaining unamortized portion of the Original Credit Agreement debt issuance costs, which will be amortized over the term of the Amended and Restated Credit Agreement. On December 31, 2017, the Company made a scheduled principal payment of $5.0 million per the terms of the Amended and Restated Credit Agreement. As of December 31, 2017, there was an outstanding debt balance issued under the term loan of the Amended and Restated Credit Agreement of $385.0 million with no borrowings outstanding against the Facility. Per the terms of the Amended and Restated Credit Agreement, a scheduled principal payment of $5.0 million is due March 31, 2018.

On September 18, 2014, the Company issued $500.0 million of 4.200% unsecured senior notes due in 2024. The senior notes were given investment grade ratings of BBB-/Baa3 with a stable outlook. The notes are subject to certain covenant restrictions and regulations which are customary for credit rated obligations. At the time of funding, the proceeds were offered at a discount of the original note amount which also excluded an underwriting fee discount. The net proceeds received from the issuance were used to repay the outstanding balance of $475.0 million on the revolving Credit Facility and for other general corporate purposes. As of December 31, 2017 and 2016, there was an outstanding debt balance of $500.0 million exclusive of the associated discount balance.

In conjunction with the acquisition of Social Security Advocates for the Disabled LLC (“SSAD”) effective February 1, 2016, the company agreed to a $0.5 million promissory note incurred as a payment to the sellers and payable after the one-year anniversary of the acquisition. The note had a nominal rate of interest 0.81%. On March 10, 2017, the promissory note was settled, plus any outstanding accrued interest, using cash.

The Master Agreement and the Amended and Restated Credit Agreement require the Company to maintain certain financial ratios and comply with certain other covenants. The Company was in compliance with all such covenants as of December 31, 2017 and 2016.

The 30-day Adjusted LIBOR Rate as of December 31, 2017 was 1.625%.

Interest paid in 2017, 2016 and 2015 was $36.2 million, $37.7 million, and $37.5 million, respectively.

At December 31, 2017, maturities of long-term debt were $120.0 million in 2018, $30.0 million in 2019, $40.0 million in 2020, $40.0 million in 2021, $255.0 million in 2022 and $500.0 million in 2024.

Income Taxes (Notes)

12 Months Ended

Dec. 31, 2017

Income Tax Disclosure [Abstract]

Income Tax Disclosure [Text Block]

Income Taxes

On December 22, 2017, the U.S. government enacted the Tax Cuts and Jobs Act of 2017 (the “Tax Reform Act”). The Tax Reform Act makes broad and complex changes to the U.S. tax code that affected our income tax rate in 2017. The Tax Reform Act reduces the U.S. federal corporate income tax rate from 35.0% to 21.0% and requires companies to pay a one-time transition tax on certain unrepatriated earnings from foreign subsidiaries that is payable over eight years. The Tax Reform Act also establishes new tax laws that became effective January 1, 2018.

ASC 740 requires a company to record the effects of a tax law change in the period of enactment, however, shortly after the enactment of the Tax Reform Act, the SEC staff issued SAB 118, which allows a company to record a provisional amount when it does not have the necessary information available, prepared, or analyzed in reasonable detail to complete its accounting for the change in the tax law. The measurement period ends when the company has obtained, prepared and analyzed the information necessary to finalize its accounting, but cannot extend beyond one year.

We have made a reasonable estimate of the impact of the Tax Reform Act and recorded a one-time credit in our 2017 income tax expense of $120.9 million, which reflects an estimated reduction in our deferred income tax liabilities of $124.2 million as a result of the maximum federal rate decreasing to 21.0% from 35.0%, which was partially offset by an estimated increase in income tax payable in the amount of $3.3 million as a result of the transition tax on cash and cash equivalent balances related to untaxed accumulated earnings associated with our international operations. We are continuing to gather additional information related to estimates surrounding the re-measurement of our deferred tax liabilities and the transition tax on unrepatriated earnings.

Significant components of the provision for income taxes for the years ended December 31 are as follows:



(in thousands)	2017			2016		2015
Current:
Federal	$	129,954		$	126,145	$	118,490
State	21,392			21,110		17,625
Foreign	929			590		430
Total current provision	152,275			147,845		136,545
Deferred:
Federal	18,999			15,551		18,416
State	2,984			2,612		4,280
Foreign	—			—		—
Tax Reform Act deferred tax revaluation	(124,166		)	—		—
Total deferred provision	(102,183		)	18,163		22,696
Total tax provision	$	50,092		$	166,008	$	159,241

A reconciliation of the differences between the effective tax rate and the federal statutory tax rate for the years ended December 31 is as follows:



	2017	2016	2015
Federal statutory tax rate	35.0%	35.0%	35.0%
State income taxes, net of federal income tax benefit	3.8	3.9	3.9
Non-deductible employee stock purchase plan expense	0.3	0.3	0.3
Non-deductible meals and entertainment	0.3	0.3	0.3
Tax Reform Act deferred tax revaluation and transition tax impact	(26.9)	—	—
Other, net	(1.4)	(0.3)	0.1
Effective tax rate	11.1%	39.2%	39.6%

Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the corresponding amounts used for income tax reporting purposes.

Significant components of Brown & Brown’s net deferred tax liabilities as of December 31 are as follows:



(in thousands)	2017			2016
Non-current deferred tax liabilities:
Intangible assets	$	306,351		$	422,478
Fixed assets	2,723			6,425
Net unrealized holding (loss)/gain on available-for-sale securities	(6		)	(12		)
Total non-current deferred tax liabilities	309,068			428,891
Non-current deferred tax assets:
Deferred compensation	36,701			44,912
Accruals and reserves	7,534			14,032
Deferred profit-sharing contingent commissions	7,107			10,567
Net operating loss carryforwards	2,434			2,394
Valuation allowance for deferred tax assets	(893		)	(700		)
Total non-current deferred tax assets	52,883			71,205
Net non-current deferred tax liability	$	256,185		$	357,686

Income taxes paid in 2017, 2016 and 2015 were $152.0 million, $143.1 million and $132.9 million, respectively.

At December 31, 2017, Brown & Brown had net operating loss carryforwards of $0.1 million and $52.2 million for federal and state income tax reporting purposes, respectively, portions of which expire in the years 2018 through 2037. The federal carryforward is derived from insurance operations acquired by Brown & Brown in 2001. The state carryforward amount is derived from the operating results of certain subsidiaries and from the 2013 stock acquisition of Beecher Carlson Holdings, Inc.

A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows:



(in thousands)	2017			2016			2015
Unrecognized tax benefits balance at January 1	$	750		$	584		$	113
Gross increases for tax positions of prior years	1,070			412			773
Gross decreases for tax positions of prior years	—			(41		)	—
Settlements	(126		)	(205		)	(302		)
Unrecognized tax benefits balance at December 31	$	1,694		$	750		$	584

The Company recognizes interest and penalties related to uncertain tax positions in income tax expense. As of December 31, 2017, 2016 and 2015 the Company had $228,608, $86,191 and $102,171 of accrued interest and penalties related to uncertain tax positions, respectively.

The total amount of unrecognized tax benefits that would affect the Company’s effective tax rate if recognized was $1.7 million as of December 31, 2017, $750,258 as of December 31, 2016 and $583,977 as of December 31, 2015. The Company does not expect its unrecognized tax benefits to change significantly over the next 12 months.

As a result of a 2006 Internal Revenue Service (“IRS”) audit, the Company agreed to accrue at each December 31, for tax purposes only, a known amount of profit-sharing contingent commissions represented by the actual amount of profit-sharing contingent commissions received in the first quarter of the related year, with a true-up adjustment to the actual amount received by the end of the following March. Since this method for tax purposes differs from the method used for book purposes, it will result in a current deferred tax asset as of December 31 each year which will reverse by the following March 31 when the related profit-sharing contingent commissions are recognized for financial accounting purposes.

The Company is subject to taxation in the United States and various state jurisdictions. The Company is also subject to taxation in the United Kingdom. In the United States, federal returns for fiscal years 2013 through 2016 remain open and subject to examination by the IRS. The Company files and remits state income taxes in various states where the Company has determined it is required to file state income taxes. The Company’s filings with those states remain open for audit for the fiscal years 2011 through 2017. In the United Kingdom, the Company’s filings remain open for audit for the fiscal years 2016 and 2017.

During 2017, the Company settled the previously disclosed IRS income tax audit of The Wright Insurance Group for the short period ended May 1, 2014. Pursuant to the agreement in which the Company acquired The Wright Insurance Group, the Company was fully indemnified for all audit-related assessments. The Company and one of its subsidiaries, The Advocator Group, LLC, is currently under examination by the State of Massachusetts for the fiscal year 2013 through 2014. There are no other federal or state income tax audits as of December 31, 2017.

As a result of the Tax Reform Act, the Company has recorded a transition tax of $3.2 million. As of December 31, 2017, the Company has estimated $20.9 million of cash and cash equivalent balances related to accumulated earnings associated with our international operations. We are continuing to gather additional information related to estimates surrounding the transition tax on unrepatriated earnings. In general, it is our practice and intention to reinvest the earnings of our non-U.S. subsidiaries in those operations.

Stock Based Compensation (Notes)

12 Months Ended

Dec. 31, 2017

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant

Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross

5,156,954

Disclosure of Compensation Related Costs, Share-based Payments [Text Block]

Stock-Based Compensation

Performance Stock Plan

In 1996, Brown & Brown adopted and the shareholders approved a performance stock plan, under which until the suspension of the plan in 2010, up to 14,400,000 Performance Stock Plan (“PSP”) shares could be granted to key employees contingent on the employees’ future years of service with Brown & Brown and other performance-based criteria established by the Compensation Committee of the Company’s Board of Directors. Before participants may take full title to Performance Stock, two vesting conditions must be met. Of the grants currently outstanding, specified portions satisfied the first condition for vesting based upon 20% incremental increases in the 20-trading-day average stock price of Brown & Brown’s common stock from the price on the business day prior to date of grant. Performance Stock that has satisfied the first vesting condition is considered “awarded shares.” Awarded shares are included as issued and outstanding common stock shares and are included in the calculation of basic and diluted EPS. Dividends are paid on awarded shares and participants may exercise voting privileges on such shares. Awarded shares satisfy the second condition for vesting on the earlier of a participant’s: (i) 15 years of continuous employment with Brown & Brown from the date shares are granted to the participants (or, in the case of the July 2009 grant to Powell Brown, 20 years), (ii) attainment of age 64 (on a prorated basis corresponding to the number of years since the date of grant), or (iii) death or disability. On April 28, 2010, the PSP was suspended and any remaining authorized, but unissued shares, as well as any shares forfeited in the future, will be reserved for issuance under the 2010 Stock Incentive Plan (the “SIP”).

At December 31, 2017, 5,156,954 shares had been granted under the PSP. As of December 31, 2017, 847,238 shares had met the first condition of vesting and had been awarded, and 4,309,716 shares had satisfied both conditions of vesting and had been distributed to participants. Of the shares that have not vested as of December 31, 2017, the initial stock prices ranged from $15.58 to $25.68.

The Company uses a path-dependent lattice model to estimate the fair value of PSP grants on the grant date.

A summary of PSP activity for the years ended December 31, 2017, 2016 and 2015 is as follows:



	Weighted- Average Grant Date Fair Value		Granted Shares		Awarded Shares		Shares Not Yet Awarded
Outstanding at January 1, 2015	$	8.71	1,928,631		1,903,213		25,418
Granted	$	—	—		—		—
Awarded	$	—	—		—		—
Vested	$	5.55	(208,889	)	(208,889	)	—
Forfeited	$	9.78	(117,528	)	(100,110	)	(17,418	)
Outstanding at December 31, 2015	$	9.03	1,602,214		1,594,214		8,000
Granted	$	—	—		—		—
Awarded	$	—	—		4,000		(4,000	)
Vested	$	6.39	(506,422	)	(506,422	)	—
Forfeited	$	10.52	(92,517	)	(88,517	)	(4,000	)
Outstanding at December 31, 2016	$	10.23	1,003,275		1,003,275		—
Granted	$	—	—		—		—
Awarded	$	—	—		—		—
Vested	$	9.61	(138,801	)	(138,801	)	—
Forfeited	$	10.47	(17,236	)	(17,236	)	—
Outstanding at December 31, 2017	$	10.32	847,238		847,238		—

The total fair value of PSP grants that vested during each of the years ended December 31, 2017, 2016 and 2015 was $6.3 million, $18.1 million and $6.8 million, respectively.

Stock Incentive Plan

On April 28, 2010, the shareholders of Brown & Brown, Inc. approved the Stock Incentive Plan (“SIP”) that provides for the granting of stock options, stock, restricted stock units, and/or stock appreciation rights to employees and directors contingent on criteria established by the Compensation Committee of the Company’s Board of Directors. The principal purpose of the SIP is to attract, incentivize and retain key employees by offering those persons an opportunity to acquire or increase a direct proprietary interest in the Company’s operations and future success. The SIP includes a sub-plan applicable to Decus Insurance Brokers Limited (“Decus”) which, is a subsidiary of Decus Holdings (U.K.) Limited. The shares of stock reserved for issuance under the SIP are any shares that are authorized for issuance under the PSP and not already subject to grants under the PSP, and that were outstanding as of April 28, 2010, the date of suspension of the PSP, together with PSP shares and SIP shares forfeited after that date. As of April 28, 2010, 6,046,768 shares were available for issuance under the PSP, which were then transferred to the SIP. In addition, in May 2016 and May 2017 our shareholders approved an amendment to the SIP to increase the shares available for issuance by an additional 1,200,000 and 1,300,000, respectively.

The Company has granted stock grants to our employees in the form of Restricted Stock Awards and Performance Stock Awards under the SIP. To date, a substantial majority of stock grants to employees under the SIP vest in four to ten years The Performance Stock Awards are subject to the achievement of certain performance criteria by grantees, which may include growth in a defined book of business, organic growth and operating profit growth of a profit center, EBITDA growth, organic growth of the Company and consolidated EPS growth at certain levels of the Company. The performance measurement period ranges from three to five years. Beginning in 2016, certain Performance Stock Awards have a payout range between 0% to 200% depending on the achievement against the stated performance target. Prior to 2016, the majority of the grants had a binary performance measurement criteria that only allowed for 0% or 100% payout.

Non-employee members of the Board of Directors received shares annually issued pursuant to the SIP as part of their annual compensation. A total of 15,700 shares were issued in January 2015, 16,860 shares were issued in January 2016 and 11,350 shares were issued in January 2017.

The following table sets forth information as of December 31, 2017, 2016 and 2015, with respect to the number of time-based restricted shares granted and awarded, the number of performance-based restricted shares granted, and the number of performance-based restricted shares awarded under our Performance Stock Plan and 2010 Stock Incentive Plan:



Year	Time-Based Restricted Stock Granted and Awarded	Performance-Based Restricted Stock Granted		Performance-Based Restricted Stock Awarded
2017	120,667	575,789	⁽¹⁾	163,404
2016	182,653	789,446	⁽²⁾	1,435,319
2015	164,646	316,520		—


(1)	Of the 575,789 shares of performance-based restricted stock granted in 2017, the payout for 320,826 shares may be increased up to 200% of the target or decreased to zero, subject to the level of performance attained. The amount reflected in the table includes all restricted stock grants at a target payout of 100%.


(2)	Of the 789,446 shares of performance-based restricted stock granted in 2016, the payout for 353,132 shares may be increased up to 200% of the target or decreased to zero, subject to the level of performance attained. The amount reflected in the table includes all restricted stock grants at a target payout of 100%.

At December 31, 2017, 4,197,920 shares were available for future grants. This amount is calculated assuming the maximum payout for all restricted stock grants.

The Company uses the closing stock price on the day prior to the grant date to determine the fair value of SIP grants and then applies an estimated forfeiture factor to estimate the annual expense. Additionally, the Company uses the path-dependent lattice model to estimate the fair value of grants with PSP-type vesting conditions as of the grant date. SIP shares that satisfied the first vesting condition for PSP-type grants or the established performance criteria are considered awarded shares. Awarded shares are included as issued and outstanding common stock shares and are included in the calculation of basic and diluted EPS.

A summary of SIP activity for the years ended December 31, 2017, 2016 and 2015 is as follows:



	Weighted- Average Grant Date Fair Value		Granted Shares		Awarded Shares		Shares Not Yet Awarded
Outstanding at January 1, 2015	$	28.19	6,659,047		1,060,890		5,598,157
Granted	$	31.74	481,166		164,646		316,520
Awarded	$	—	—		—		—
Vested	$	—	—		—		—
Forfeited	$	26.32	(863,241	)	(95,542	)	(767,699	)
Outstanding at December 31, 2015	$	28.74	6,276,972		1,129,994		5,146,978
Granted	$	35.52	972,099		182,653		789,446		⁽¹⁾
Awarded	$	24.93	—		1,431,319		(1,431,319	)
Vested	$	27.31	(166,884	)	(166,884	)	—
Forfeited	$	25.34	(954,131	)	(175,788	)	(778,343	)
Outstanding at December 31, 2016	$	29.96	6,128,056		2,401,294		3,726,762
Granted	$	41.65	696,456		120,667		575,789		⁽²⁾
Awarded	$	31.44	—		163,404		(163,404	)
Vested	$	25.22	(242,457	)	(242,457	)	—
Forfeited	$	29.77	(171,060	)	(38,106	)	(132,954	)
Outstanding at December 31, 2017	$	31.16	6,410,995		2,404,802		4,006,193


(1)	Of the 789,446 shares of performance-based restricted stock granted in 2016, the payout for 353,132 shares may be increased up to 200% of the target or decreased to zero, subject to the level of performance attained. The amount reflected in the table includes all restricted stock grants at a target payout of 100%.


(2)	Of the 575,789 shares of performance-based restricted stock granted in 2016, the payout for 320,826 shares may be increased up to 200% of the target or decreased to zero, subject to the level of performance attained. The amount reflected in the table includes all restricted stock grants at a target payout of 100%.

Employee Stock Purchase Plan

The Company has a shareholder-approved Employee Stock Purchase Plan (“ESPP”) with a total of 17,000,000 authorized shares of which 4,151,251 were available for future subscriptions as of December 31, 2017. Employees of the Company who regularly work 20 hours or more per week are eligible to participate in the ESPP. Participants, through payroll deductions, may allot up to 10% of their compensation towards the purchase of a maximum of $25,000 worth of Company stock between August 1st of each year and the following July 31st (the “Subscription Period”) at a cost of 85% of the lower of the stock price as of the beginning or end of the Subscription Period.

The Company estimates the fair value of an ESPP share option as of the beginning of the Subscription Period as the sum of: (1) 15% of the quoted market price of the Company’s stock on the day prior to the beginning of the Subscription Period, and (2) 85% of the value of a one-year stock option on the Company stock using the Black-Scholes option-pricing model. The estimated fair value of an ESPP share option as of the Subscription Period beginning in August 2017 was $8.64. The fair values of an ESPP share option as of the Subscription Periods beginning in August 2016 and 2015, were $7.61 and $6.43, respectively.

For the ESPP plan years ended July 31, 2017, 2016 and 2015, the Company issued 529,012, 514,665 and 539,389 shares of common stock, respectively. These shares were issued at an aggregate purchase price of $16.4 million, or $31.03 per share, in 2017, $15.0 million, or $29.23 per share, in 2016, and $14.4 million, or $26.62 per share, in 2015.

For the five months ended December 31, 2017, 2016 and 2015 (portions of the 2017-2018, 2016-2017 and 2015-2016 plan years), 217,514, 247,023 and 231,803 shares of common stock (from authorized but unissued shares), respectively, were subscribed to by ESPP participants for proceeds of approximately $8.2 million, $7.7 million and $6.8 million, respectively.

Incentive Stock Option Plan

On April 21, 2000, Brown & Brown adopted, and the shareholders approved, a qualified incentive stock option plan (the “ISOP”) that provides for the granting of stock options to certain key employees for up to 4,800,000 shares of common stock. On December 31, 2008, the ISOP expired. The objective of the ISOP was to provide additional performance incentives to grow Brown & Brown’s pre-tax income in excess of 15% annually. The options were granted at the most recent trading day’s closing market price and vest over a period of 1-to-10 years , with a potential acceleration of the vesting period to 3-to-6 years based upon achievement of certain performance goals. All of the options expire 10 years after the grant date.

The Company uses the Black-Scholes option-pricing model to estimate the fair value of stock options on the grant date. The risk-free interest rate is based upon the U.S. Treasury yield curve on the date of grant with a remaining term approximating the expected term of the option granted. The expected term of the options granted is derived from historical data; grantees are divided into two groups based upon expected exercise behavior and are considered separately for valuation purposes. The expected volatility is based upon the historical volatility of the Company’s common stock over the period of time equivalent to the expected term of the options granted. The dividend yield is based upon the Company’s best estimate of future dividend yield.

A summary of stock option activity for the years ended December 31, 2017, 2016 and 2015 is as follows:



Stock Options	Shares Under Option		Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value (in thousands)
Outstanding at January 1, 2015	470,356		$	18.57	3.1	$	5,087
Granted	—		$	—
Exercised	(151,767	)	$	18.48
Forfeited	(49,000	)	$	19.36
Expired	—		$	—
Outstanding at December 31, 2015	269,589		$	18.48	2.2	$	2,395
Granted	—		$	—
Exercised	(64,589	)	$	18.48
Forfeited	(30,000	)	$	18.48
Expired	—		$	—
Outstanding at December 31, 2016	175,000		$	18.48	1.2	$	4,616
Granted	—		$	—
Exercised	(175,000	)	$	18.48
Forfeited	—		$	—
Expired	—		$	—
Outstanding at December 31, 2017	—		$	—	N/A	$	—
Ending vested and expected to vest at December 31, 2017	—		$	—	N/A	$	—
Exercisable at December 31, 2017	—		$	—	N/A	$	—
Exercisable at December 31, 2016	175,000		$	18.48	1.2	$	4,616
Exercisable at December 31, 2015	164,589		$	18.48	2.2	$	2,241

The total intrinsic value of options exercised, determined as of the date of exercise, during the years ended December 31, 2017, 2016 and 2015 was $4.7 million, $1.0 million and $2.2 million, respectively. The total intrinsic value is calculated as the difference between the exercise price of all underlying awards and the quoted market price of the Company’s stock for all in-the-money stock options at December 31, 2017, 2016 and 2015, respectively.

There are no option shares available for future grant under the ISOP since this plan expired as of December 31, 2008.

Summary of Non-Cash Stock-Based Compensation Expense

The non-cash stock-based compensation expense for the years ended December 31 is as follows:



(in thousands)	2017		2016		2015
Stock Incentive Plan	$	24,899	$	11,049	$	11,111
Employee Stock Purchase Plan	4,025		3,698		3,430
Performance Stock Plan	1,707		1,305		972
Incentive Stock Option Plan	—		—		—
Total	$	30,631	$	16,052	$	15,513

Summary of Unamortized Compensation Expense

As of December 31, 2017, there was approximately $87.9 million of unamortized compensation expense related to all non-vested stock-based compensation arrangements granted under the Company’s stock-based compensation plans. That expense is expected to be recognized over a weighted-average period of 3.62 years.

- Definition

The entire disclosure for compensation-related costs for equity-based compensation, which may include disclosure of policies, compensation plan details, allocation of equity compensation, incentive distributions, equity-based arrangements to obtain goods and services, deferred compensation arrangements, employee stock ownership plan details and employee stock purchase plan details.

+ References + Details

Supplemental Disclosures of Cash Flow Information and Non-Cash Financing and Investing Activities

12 Months Ended

Dec. 31, 2017

Supplemental Cash Flow Elements [Abstract]

Supplemental Disclosures of Cash Flow Information and Non-Cash Financing and Investing Activities

The following is a reconciliation of cash and cash equivalents inclusive of restricted cash as of December 31, 2017, 2016 and 2015.



	Balance as of December 31,
(in thousands)	2017		2016		2015
Table to reconcile cash and cash equivalents inclusive of restricted cash
Cash and cash equivalents	$	573,383	$	515,646	443,420
Restricted cash	250,705		265,637		229,753
Total cash and cash equivalents inclusive of restricted cash at the end of the period	$	824,088	$	781,283	673,173

Quarterly Operating Results (Notes)

12 Months Ended

Dec. 31, 2017

Quarterly Financial Information Disclosure [Abstract]

Quarterly Financial Information [Text Block]

Quarterly Operating Results (Unaudited)

Quarterly operating results for 2017 and 2016 were as follows:



(in thousands, except per share data)	First Quarter		Second Quarter		Third Quarter		Fourth Quarter
2017
Total revenues	$	465,080	$	466,305	$	475,646	$	474,316
Total expenses	$	354,113	$	358,303	$	351,227	$	367,982
Income before income taxes	$	110,967	$	108,002	$	124,419	$	106,334
Net income	$	70,110	$	66,102	$	75,913	$	187,505
Net income per share:
Basic	$	0.50	$	0.47	$	0.54	$	1.35
Diluted	$	0.49	$	0.46	$	0.53	$	1.32	⁽¹⁾
2016
Total revenues	$	424,173	$	446,518	$	462,274	$	433,664
Total expenses	$	321,624	$	337,441	$	345,302	$	338,763
Income before income taxes	$	102,549	$	109,077	$	116,972	$	94,901
Net income	$	62,070	$	66,250	$	71,545	$	57,626
Net income per share:
Basic	$	0.45	$	0.47	$	0.51	$	0.41
Diluted	$	0.44	$	0.47	$	0.50	$	0.41


(1)	Includes $0.85 impact associated with recording impact of Tax Reform Act.

Quarterly financial results are affected by seasonal variations. The timing of the Company’s receipt of profit-sharing contingent commissions, policy renewals and acquisitions may cause revenues, expenses and net income to vary significantly between quarters.

Segment Information

12 Months Ended

Dec. 31, 2017

Segment Reporting [Abstract]

Segment Information

Brown & Brown’s business is divided into four reportable segments: (1) the Retail Segment, which provides a broad range of insurance products and services to commercial, public and quasi-public entities, and to professional and individual customers, (2) the National Programs Segment, which acts as a MGA, provides professional liability and related package products for certain professionals, a range of insurance products for individuals, flood coverage, and targeted products and services designated for specific industries, trade groups, governmental

entities and market niches, all of which are delivered through nationwide networks of independent agents, and Brown & Brown retail agents, (3) the Wholesale Brokerage Segment, which markets and sells excess and surplus commercial and personal lines insurance, primarily through independent agents and brokers, as well as Brown & Brown retail agents, and (4) the Services Segment, which provides insurance-related services, including third-party claims administration and comprehensive medical utilization management services in both the workers’ compensation and all-lines liability arenas, as well as Medicare Set-aside services, Social Security disability and Medicare benefits advocacy services and claims adjusting services.

Brown & Brown conducts all of its operations within the United States of America, except for a Wholesale Brokerage operation based in London, England, and Retail operations in Bermuda and the Cayman Islands. These operations earned $15.9 million, $14.5 million and $13.4 million of total revenues for the years ended December 31, 2017, 2016 and 2015, respectively. Long-lived assets held outside of the United States during each of these three years were not material. Additionally, we have a licenses to operate as a broker in various Canadian provinces.

The accounting policies of the reportable segments are the same as those described in Note 1. The Company evaluates the performance of its segments based upon revenues and income before income taxes. Inter-segment revenues are eliminated.

Summarized financial information concerning the Company’s reportable segments is shown in the following table. The “Other” column includes any income and expenses not allocated to reportable segments and corporate-related items, including the intercompany interest expense charge to the reporting segment.



	For the year ended December 31, 2017
(in thousands)	Retail		National Programs		Wholesale Brokerage		Services		Other			Total
Total revenues	$	943,460	$	479,813	$	271,737	$	165,372	$	20,965		$	1,881,347
Investment income	$	8	$	384	$	—	$	299	$	935		$	1,626
Amortization	$	42,164	$	27,277	$	11,456	$	4,548	$	1		$	85,446
Depreciation	$	5,210	$	6,325	$	1,885	$	1,600	$	7,678		$	22,698
Interest expense	$	31,133	$	35,561	$	6,263	$	3,522	$	(38,163	)	$	38,316
Income before income taxes	$	196,616	$	109,961	$	68,844	$	30,498	$	43,803		$	449,722
Total assets	$	4,255,515	$	3,267,486	$	1,260,239	$	399,240	$	(3,434,930	)	$	5,747,550
Capital expenditures	$	4,494	$	5,936	$	1,836	$	1,033	$	10,893		$	24,192



	For the year ended December 31, 2016
(in thousands)	Retail		National Programs		Wholesale Brokerage		Services		Other			Total
Total revenues	$	917,406	$	448,516	$	243,103	$	156,365	$	1,239		$	1,766,629
Investment income	$	37	$	628	$	4	$	283	$	504		$	1,456
Amortization	$	43,447	$	27,920	$	10,801	$	4,485	$	10		$	86,663
Depreciation	$	6,191	$	7,868	$	1,975	$	1,881	$	3,088		$	21,003
Interest expense	$	38,216	$	45,738	$	3,976	$	4,950	$	(53,399	)	$	39,481
Income before income taxes	$	188,001	$	91,762	$	62,623	$	24,338	$	56,775		$	423,499
Total assets⁽¹⁾	$	3,854,393	$	2,711,378	$	1,108,829	$	371,645	$	(2,783,511	)	$	5,262,734
Capital expenditures	$	5,951	$	6,977	$	1,301	$	656	$	2,880		$	17,765



	For the year ended December 31, 2015
(in thousands)	Retail		National Programs		Wholesale Brokerage		Services		Other			Total
Total revenues	$	870,346	$	428,734	$	216,996	$	145,365	$	(932	)	$	1,660,509
Investment income	$	87	$	210	$	150	$	42	$	515		$	1,004
Amortization	$	45,145	$	28,479	$	9,739	$	4,019	$	39		$	87,421
Depreciation	$	6,558	$	7,250	$	2,142	$	1,988	$	2,952		$	20,890
Interest expense	$	41,036	$	55,705	$	891	$	5,970	$	(64,354	)	$	39,248
Income before income taxes	$	181,938	$	67,673	$	64,708	$	19,713	$	68,527		$	402,559
Total assets⁽¹⁾	$	3,507,476	$	2,503,537	$	895,782	$	285,459	$	(2,212,410	)	$	4,979,844
Capital expenditures	$	6,797	$	6,001	$	3,084	$	1,088	$	1,405		$	18,375

(1)

Total assets have been restated to reflect the adoption of ASU No. 2015-17, “Income Taxes (Topic 740) - Balance Sheet Classification of Deferred Taxes” (“ASU 2015-17”).

- Definition

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

+ References

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+ Details

Losses and Loss Adjustment Reserve

12 Months Ended

Dec. 31, 2017

Reinsurance Disclosures [Abstract]

Losses and Loss Adjustment Reserve

Although the reinsurers are liable to the Company for amounts reinsured, our subsidiary, WNFIC remains primarily liable to its policyholders for the full amount of the policies written whether or not the reinsurers meet their obligations to the Company when they become due. The effects of reinsurance on premiums written and earned at December 31 are as follows:



	2017				2016
(in thousands)	Written		Earned		Written		Earned
Direct premiums	$	604,623	$	592,267	$	591,142	$	592,123
Assumed premiums	—		—		—		—
Ceded premiums	604,610		592,254		591,124		592,105
Net premiums	$	13	$	13	$	18	$	18

All premiums written by WNFIC under the National Flood Insurance Program are 100% ceded to FEMA, for which WNFIC received a 30.9% expense allowance from January 1, 2017 through December 31, 2017. As of December 31, 2017 and 2016, the Company ceded $602.9 million and $589.5 million of written premiums, respectively.

Effective April 1, 2014, WNFIC is also a party to a quota share agreement whereby it cedes 100% of its gross excess flood premiums, excluding fees, to Arch Reinsurance Company and receives a 30.5% commission. WNFIC ceded $1.7 million and $1.6 million for the years ended December 31, 2017 and 2016. As of December 31, 2017, WNFIC had $1.1 million in paid excess flood losses, $16,606 in loss adjustment expenses, case reserves of $838,307 and incurred but not reported of $1.5 million.

WNFIC also ceded 100%, of the Homeowners, Private Passenger Auto Liability, and Other Liability Occurrence to Stillwater Insurance Company, formerly known as Fidelity National Insurance Company. This business is in runoff. Therefore, only loss data still exists on this business. As of December 31, 2017, no ceded unpaid losses and loss adjustment expenses or incurred but not reported balance for Homeowners, Private Passenger Auto Liability and Other Liability Occurrence.

As of December 31, 2017, the Consolidated Balance Sheet contained Reinsurance recoverable of $477.8 million and Prepaid reinsurance premiums of $321.0 million. As of December 31, 2016, the Consolidated Balance Sheet contained reinsurance recoverable of $78.1 million and prepaid reinsurance premiums of $308.7 million. There was $1.1 million net activity in the reserve for losses and loss adjustment expense for the year ended December 31, 2017, and no net activity in the reserve for losses and loss adjustment expense for the year ended December 31, 2016, as WNFIC’s direct premiums written were 100% ceded to two reinsurers. The balance of the reserve for losses and loss adjustment expense, excluding related reinsurance recoverables was $477.8 million as of December 31, 2017 and $78.1 million as of December 31, 2016.

Shareholders' Equity	12 Months Ended
Shareholders' Equity	Dec. 31, 2017
Equity [Abstract]
Shareholders' Equity	Shareholders’ Equity On July 18, 2014, the Company’s Board of Directors authorized the repurchase of up to $200.0 million of its shares of common stock, and on July 20, 2015, the Company’s Board of Directors authorized the repurchase of up to an additional $400.0 million of the Company’s outstanding common stock. Under the authorization from the Company’s Board of Directors, shares may be purchased from time to time, at the Company’s discretion and subject to the availability of stock, market conditions, the trading price of the stock, alternative uses for capital, the Company’s financial performance and other potential factors. These purchases may be carried out through open market purchases, block trades, accelerated share repurchase plans of up to $100.0 million each (unless otherwise approved by the Board of Directors), negotiated private transactions or pursuant to any trading plan that may be adopted in accordance with Rule 10b5-1 of the Securities Exchange Act of 1934. Between May 18, 2017 and July 14, 2017, the Company made share repurchases in the open market in total of 348,460 shares at a total cost of $14.9 million. On August 14, 2017, the Company entered into accelerated share repurchase agreement ("ASR") with an investment bank to purchase an aggregate $50.0 million of the Company's common stock. As part of the ASR, the company received an initial delivery of 967,888 shares of the Company's common stock with a fair market value of approximately $42.5 million. Upon maturity of the program, the Company received 108,288 shares, relieving the remaining balance of $7.5 million at settlement on October 16, 2017 for a total delivery of 1,076,176 shares of the Company's common stock. On November 14, 2017, the Company entered into an ASR with an investment bank to purchase an aggregate $75.0 million of the Company's common stock. As part of the ASR, the company received an initial delivery of 1,290,486 shares of the Company's common stock with a fair market value of approximately $63.8 million. Upon maturity of the program, the Company received 168,227 shares, relieving the remaining balance of $11.2 million at settlement on February 9, 2018 for a total delivery of 1,458,713 shares of the Company's common stock. During 2014, the Company repurchased 2,384,760 shares at an average price per share of $31.46 for a total cost of $75.0 million under the original share repurchase authorization from the Board of Directors on July 18, 2014. During 2015, the Company repurchased 5,408,819 shares at an average price per share of $32.35 for a total cost of $175.0 million under the current share repurchase authorization, while exhausting the previous authorization of $200.0 million from the Board of Directors in 2014. During 2016, the Company repurchased 209,618 shares at an average price per share of $36.53 for a total cost of $7.7 million under the current share repurchase authorization. At December 31, 2017, the remaining amount authorized by our Board of Directors for share repurchases was $238.7 million. Under the authorized repurchase programs, the Company has repurchased a total of approximately 10.7 million shares for an aggregate cost of approximately $386.3 million between 2014 and 2017.

- Definition

The entire disclosure for shareholders' equity comprised of portions attributable to the parent entity and noncontrolling interest, including other comprehensive income. Includes, but is not limited to, balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings, accumulated balance for each classification of other comprehensive income and amount of comprehensive income.

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+ Details

Legal and Regulatory Proceedings

12 Months Ended

Dec. 31, 2017

Commitments and Contingencies Disclosure [Abstract]

Legal and Regulatory Proceedings

Operating Leases

Brown & Brown leases facilities and certain items of office equipment under non-cancelable operating lease arrangements expiring on various dates through 2042. The facility leases generally contain renewal options and escalation clauses based upon increases in the lessors’ operating expenses and other charges. Brown & Brown anticipates that most of these leases will be renewed or replaced upon expiration. At December 31, 2017, the aggregate future minimum lease payments under all non-cancelable lease agreements were as follows:



(in thousands)
2018	$	42,970
2019	39,005
2020	34,236
2021	27,715
2022	21,996
Thereafter	44,496
Total minimum future lease payments	$	210,418

Rental expense in 2017, 2016 and 2015 for operating leases totaled $51.0 million, $49.3 million and $46.0 million, respectively.

Legal Proceedings

The Company records losses for claims in excess of the limits of, or outside the coverage of, applicable insurance at the time and to the extent they are probable and estimable. In accordance with ASC Topic 450-Contingencies, the Company accrues anticipated costs of settlement, damages, losses for liability claims and, under certain conditions, costs of defense, based upon historical experience or to the extent specific losses are probable and estimable. Otherwise, the Company expenses these costs as incurred. If the best estimate of a probable loss is a range rather than a specific amount, the Company accrues the amount at the lower end of the range.

The Company’s accruals for legal matters that were probable and estimable were not material at December 31, 2017 and 2016. We continue to assess certain litigation and claims to determine the amounts, if any, that management believes will be paid as a result of such claims and litigation and, therefore, additional losses may be accrued and paid in the future, which could adversely impact the Company’s operating results, cash flows and overall liquidity. The Company maintains third-party insurance policies to provide coverage for certain legal claims, in an effort to mitigate its overall exposure to unanticipated claims or adverse decisions. However, as (i) one or more of the Company’s insurance carriers could take the position that portions of these claims are not covered by the Company’s insurance, (ii) to the extent that payments are made to resolve claims and lawsuits, applicable insurance policy limits are eroded and (iii) the claims and lawsuits relating to these matters are continuing to develop, it is possible that future results of operations or cash flows for any particular quarterly or annual period could be materially affected by unfavorable resolutions of these matters. Based upon the AM Best Company ratings of these third-party insurers, management does not believe there is a substantial risk of an insurer’s material non-performance related to any current insured claims.

On the basis of current information, the availability of insurance and legal advice, in management’s opinion, the Company is not currently involved in any legal proceedings which, individually or in the aggregate, would have a material adverse effect on its financial condition, operations and/or cash flows.

Summary of Significant Accounting Policies (Policies)	12 Months Ended
Summary of Significant Accounting Policies (Policies)	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Average Annual Operating Profit Earned Period Maximum	3 years
Fair Value of Financial Instruments, Policy [Policy Text Block]	Fair Value of Financial Instruments The carrying amounts of Brown & Brown’s financial assets and liabilities, including cash and cash equivalents; restricted cash and short-term investments; investments; premiums, commissions and fees receivable; reinsurance recoverable; prepaid reinsurance premiums; premiums payable to insurance companies; losses and loss adjustment reserve; unearned premium; premium deposits and credits due customers and accounts payable, at December 31, 2017 and 2016, approximate fair value because of the short-term maturity of these instruments. The carrying amount of Brown & Brown’s long-term debt approximates fair value at December 31, 2017 and 2016 as our fixed-rate borrowings of $598.9 million approximate their values using market quotes of notes with the similar terms as ours, which we deem a close approximation of current market rates. Of the $598.9 million, $100.0 million is related to short-term notes which approximates the carrying value due to the proximity to maturity. The estimated fair value of the $385.0 million remaining on the term loan under our Amended and Restated Credit Facility (as defined below) approximates the carrying value due to the variable interest rate based upon adjusted LIBOR. See Note 2 to our Consolidated Financial Statements for the fair values related to the establishment of intangible assets and the establishment and adjustment of earn-out payables. See Note 5 for information on the fair value of investments and Note 8 for information on the fair value of long-term debt.
Nature of Operations	Summary of Significant Accounting Policies Nature of Operations Brown & Brown, Inc., a Florida corporation, and its subsidiaries (collectively, “Brown & Brown” or the “Company”) is a diversified insurance agency, wholesale brokerage, insurance programs and services organization that markets and sells to its customers, insurance products and services, primarily in the property, casualty and employee benefits areas. Brown & Brown’s business is divided into four reportable segments: the Retail Segment provides a broad range of insurance products and services to commercial, public and quasi-public entities, professional and individual customers; the National Programs Segment, acting as a managing general agent (“MGA”), provides professional liability and related package products for certain professionals, a range of insurance products for individuals, flood coverage, and targeted products and services designated for specific industries, trade groups, governmental entities and market niches, all of which are delivered through nationwide networks of independent agents, including Brown & Brown retail agents; the Wholesale Brokerage Segment markets and sells excess and surplus commercial insurance, primarily through independent agents and brokers, as well as Brown & Brown Retail offices; and the Services Segment provides insurance-related services, including third-party claims administration and comprehensive medical utilization management services in both the workers’ compensation and all-lines liability arenas, as well as Medicare Set-aside services, Social Security disability and Medicare benefits advocacy services, and claims adjusting services. Recently Issued Accounting Pronouncements In November 2016, the Financial Accountings Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-18, “Statement of Cash Flows (Topic 230)”: Restricted Cash (“ASU 2016-18”), which requires that the Statement of Cash Flows explain the changes during the period of cash and cash equivalents inclusive of amounts categorized as restricted cash. ASU 2016-18 is effective for periods beginning after December 15, 2017. However, the Company elected to early adopt for the reporting period beginning January 1, 2017 under the full retrospective approach for all periods presented. With the adoption of ASU 2016-18, the change in restricted cash is no longer reflected as a change in operating assets and liabilities, and the Statement of Cash Flows details the changes in the balance of cash and cash equivalents inclusive of restricted cash. Net cash provided by operating activities for the years ended December 31, 2015 and 2016 were previously reported as $411.8 million and $375.2 million, respectively. With the retrospective adoption, the net cash provided by operating activities for the years ended December 31, 2015 and 2016 is now reported as $381.8 million and $411.0 million, respectively. The Company reflects cash collected from customers that is payable to insurance companies as restricted cash if segregation of this cash is required by the state of domicile for the office conducting this transaction or if required by contract with the relevant insurance company providing coverage. Cash collected from customers that is payable to insurance companies is reported in cash and cash equivalents if no such restriction is required. In August 2016, the FASB issued ASU 2016-15, “Statement of Cash Flows (Topic 230)”: Classification of Certain Cash Receipts and Cash Payments (a consensus of the Emerging Issues Task Force) (“ASU 2016-15”), which addresses eight specific cash flow issues with the objective of reducing the existing diversity in practice in how certain cash receipts and cash payments are presented and classified and applies to all entities, including both business entities and not-for-profit entities that are required to present a statement of cash flows under Topic 230. ASU 2016-15 will take effect for public companies for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2017 and early adoption is permitted. The Company is adopting this change effective January 1, 2018 and has evaluated the impact of ASU 2016-15 determining that there is no impact on the Company’s Statement of Cash Flows. The Company already presents cash paid on contingent consideration in business combination as prescribed by ASU 2016-15 and does not, at this time, engage in the other activities being addressed. In March 2016, the FASB issued ASU 2016-09, “Improvements to Employee Share Based Payment Accounting” (“ASU 2016-09”), which amends guidance issued in Accounting Standards Codification (“ASC”) Topic 718, Compensation - Stock Compensation. ASU 2016-09 simplifies several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. ASU 2016-09 is effective for fiscal years beginning after December 15, 2016, and interim periods within those fiscal years and early adoption is permitted. The Company adopted the guidance on January 1, 2017, as required. Prior periods have not been adjusted, as the guidance was adopted prospectively. The principal impact is that the tax benefit or expense from stock compensation is now presented in the income tax line of the Statement of Income, whereas the prior treatment was to present this amount as a component of equity on the Balance Sheet. In addition, the tax benefit or expense is now presented as activity in Cash Flow from Operating Activity, rather than the prior presentation as Cash Flow from Financing Activity in the Statement of Cash Flows. The Company also continues to estimate forfeitures of stock grants as allowed by ASU 2016-09. In March 2016, the FASB issued ASU 2016-08, “Principal Versus Agent Considerations (Reporting Revenue Gross Versus Net)” (“ASU 2016-08”) to clarify certain aspects of the principal-versus-agent guidance included in the new revenue standard ASU 2014-09 “Revenue from Contracts with Customers” (“ASU 2014-09”). The FASB issued the ASU in response to concerns identified by stakeholders, including those related to (1) determining the appropriate unit of account under the revenue standard’s principal-versus-agent guidance and (2) applying the indicators of whether an entity is a principal or an agent in accordance with the revenue standard’s control principle. ASU 2016-08 is effective contemporaneous with ASU 2014-09 beginning January 1, 2018. The impact of adopting ASU 2016-08 is not material to the Company. In February 2016, the FASB issued ASU 2016-02, “Leases (Topic 842)” (“ASU 2016-02”), which provides guidance for accounting for leases. Under ASU 2016-02, the Company will be required to recognize the assets and liabilities for the rights and obligations created by leased assets. ASU 2016-02 will take effect for public companies for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. The Company continues to evaluate the impact of this pronouncement with the principal impact being that the present value of the remaining lease payments be presented as a liability on the Balance Sheet as well as an asset of similar value representing the “Right of Use” for those leased properties. As detailed in Note 13 of the 2016 10-K, the undiscounted contractual cash payments remaining on leased properties was $213.2 million as of December 31, 2016 and is $210.4 million as of December 31, 2017 as detailed in “Management’s Discussion and Analysis of Financial Condition and Results of Operations - Liquidity and Capital Resources” and Note 13 “Commitments and Contingencies.” In November 2015, FASB issued ASU No. 2015-17, “Income Taxes (Topic 740) - Balance Sheet Classification of Deferred Taxes” (“ASU 2015-17”), which simplifies the presentation of deferred income taxes by requiring deferred tax assets and liabilities be classified as a single non-current item on the balance sheet. ASU 2015-17 is effective for fiscal years beginning after December 15, 2016 with early adoption permitted as of the beginning of any interim or annual reporting period. The Company adopted the guidance on January 1, 2017, as required. As a result, the Company retrospectively applied the guidance to the 2016 balance sheet by reclassifying $24.6 million from deferred income taxes (asset) to deferred income taxes, net (liability) on the Condensed Consolidated Balance Sheet. This reclassification occurred prior to the passage of the Tax Cuts and Jobs Act of 2017, which had a material impact on the value of deferred tax items. See Note 9 “Income Taxes” for more information. In May 2014, FASB issued ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606)” (“Topic 606”), which provides guidance for revenue recognition. Topic 606 affects any entity that either enters into contracts with customers to transfer goods or services or enters into contracts for the transfer of non-financial assets. It supersedes the revenue recognition requirements in Topic 605, “Revenue Recognition,” and most industry-specific guidance. The standard’s core principle is that a company should recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which a company expects to be entitled in exchange for those goods or services. In doing so, companies will need to use more judgment and make more estimates than under the current guidance. Specifically, in situations where multiple performance obligations exist within a contract, the use of estimates is required to allocate the transaction price to each separate performance obligation. Historically, approximately 70% of the Company’s commissions and fees are in the form of commissions paid by insurance carriers. These commissions are earned upon the effective date of bound coverage, as no significant performance obligation remains after coverage is bound. The following areas are impacted by the adoption of Topic 606: Installment billing - Prior to the adoption of Topic 606, commission revenues related to installment billings were recognized on the latter of the policy effective date (as indicated in the policy) or the date that the premium was billed to the client (as indicated on the premium invoice), with the exception of our Arrowhead businesses, which follow a policy of recognizing these revenues on the latter of the policy effective date or processed date into our systems, regardless of the billing arrangement. As a result of the adoption of Topic 606, revenue associated with the issuance of policies will be recognized upon the effective date of the associated policy, which means that commission revenues billed on an installment basis will be now recognized earlier than they had been previously resulting in revenue will accrued based upon the completion of the performance obligation and thus creating a current asset for the unbilled revenue until such time as an invoice is generated, typically not to exceed twelve months. The Company does not expect the overall impact of these changes to be significant on a full-year basis, but the timing of recognizing revenue will be impacted among quarters when compared to prior years. Contingent commissions - Prior to the adoption of Topic 606, revenue that was not fixed and determinable because a contingency exists was not recognized until the contingency was resolved. Under Topic 606, the Company must use its judgment to estimate the amount of consideration that will be received such that a significant reversal of revenue is not probable. Contingent commissions represent a form of variable consideration associated with the same performance obligation, which is the placement of coverage, for which we earn core commissions. In connection with the new standard, contingent commissions will be estimated with an appropriate constraint applied and accrued relative to the recognition of the corresponding core commissions. The resulting effect on the timing of recognition of contingent commissions will more closely follow a similar pattern as our core commissions with true-ups recognized when payments are received or as additional information that affects the estimate becomes available. Contingent commissions have averaged approximately 3.6% of the previous year’s total commissions and fees over the last three years and have primarily been received in the first and second quarters of the year. Approximately 30% of the Company’s commissions and fees is in the form of fees, which are predominantly in our National Programs and Services Segments, and to a lesser extent in the large accounts business within our Retail Segment, where we receive fees in lieu of a commission. In accordance with Topic 606, fee revenue from certain agreements will be recognized in earlier periods and others in later periods as compared to our current accounting treatment. The Company does not expect the overall impact of these changes to be significant on a full-year basis, but the timing of recognizing revenue will be impacted among quarters when compared to prior years. Additionally, the Company has evaluated ASC Topic 340 - Other Assets and Deferred Cost (“ASC 340”) which requires companies to defer certain incremental costs to obtain customer contracts, and certain costs to fulfill customer contracts. Incremental cost to obtain - the adoption of ASC 340 will result in the Company deferring certain cost to obtain customer contracts primarily as they relate to commission based compensation plans in the Retail Segment, in which the Company pays an incremental amount of compensation on new business in the first year of the contract. These incremental costs will be deferred and amortized over a 15-year period, which is consistent with the analysis performed on acquired customer accounts and referenced in Note 4 to the Company’s financial statements. Cost to fulfill - the adoption of ASC 340 will result in the Company deferring certain costs to fulfill a contract and recognize these costs as the associated performance obligations are fulfilled. In order for contract fulfillment costs to be deferred under ASC 340, the costs must (1) relate directly to a specific contract or anticipated contract, (2) generate or enhance resources that the Company will use in satisfying its obligations under the contract, and (3) be expected to be recovered through sufficient net cash flows from the contract. The Company does not expect the overall impact of these changes to be significant on a full-year basis, but the timing of recognizing these expenses will be impacted among quarters to better align with the associated revenue. Topic 606 is effective for the Company beginning January 1, 2018. Entities are permitted to adopt the guidance under one of the following methods: the “full retrospective” method, which applies the guidance to each period presented (prior years restated), or the “modified retrospective” method, in which the guidance is only applied to the year of adoption, with the cumulative effect of initially applying the guidance recognized as an adjustment to retained earnings. The Company has elected to follow the modified retrospective method applied to contracts that are not completed as of the date of adoption. The estimated cumulative impact of adopting the standard on January 1, 2018 is an increase in stockholders’ equity of between $70.0 million and $110.0 million. In connection with the implementation of this standard, we expect to modify, and in some instances institute additional accounting procedures, processes and internal controls. Given the relative expected impacts of this standard to our revenue streams, we do not expect that these modifications and additions will materially change our internal controls over financial reporting. Principles of Consolidation The accompanying Consolidated Financial Statements include the accounts of Brown & Brown, Inc. and its subsidiaries. All significant intercompany account balances and transactions have been eliminated in the Consolidated Financial Statements. Segment results for prior periods have been recast, where appropriate, to reflect the current year segmental structure. Certain reclassifications have been made to the prior year amounts reported in this Annual Report on Form 10-K in order to conform to the current year presentation. Revenue Recognition Commission revenues are recognized as of the effective date of the insurance policy or the date on which the policy premium is processed into our systems and invoiced to the customer, whichever is later. Commission revenues related to installment billings are recognized on the latter of effective or invoiced date, with the exception of our Arrowhead business which follows a policy of recognizing on the latter of effective or processed date into our systems, regardless of the billing arrangement. Management determines the policy cancellation reserve based upon historical cancellation experience adjusted for any known circumstances. Subsequent commission adjustments were recognized upon our receipt of notification from insurance companies concerning matters necessitating such adjustments. Profit-sharing contingent commissions are recognized when determinable, which is generally when such commissions are received from insurance companies, or when we receive formal notification of the amount of such payments. Fee revenues and commissions for workers’ compensation programs are recognized as services are rendered. Use of Estimates The preparation of the Consolidated Financial Statements in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, as well as disclosures of contingent assets and liabilities, at the date of the Consolidated Financial Statements, and the reported amounts of revenues and expenses during the reporting period. Actual results may differ from those estimates. Cash and Cash Equivalents Cash and cash equivalents principally consist of demand deposits with financial institutions and highly liquid investments with quoted market prices having maturities of three months or less when purchased. Restricted Cash and Investments, and Premiums, Commissions and Fees Receivable In our capacity as an insurance agent or broker, the Company typically collects premiums from insureds and, after deducting the authorized commissions, remits the net premiums to the appropriate insurance company or companies. Accordingly, as reported in the Consolidated Balance Sheets, “premiums” are receivable from insureds. Unremitted net insurance premiums are held in a fiduciary capacity until Brown & Brown disburses them. Where allowed by law, Brown & Brown invests these unremitted funds only in cash, money market accounts, tax-free variable-rate demand bonds and commercial paper held for a short term. In certain states in which Brown & Brown operates, the use and investment alternatives for these funds are regulated and restricted by various state laws and agencies. These restricted funds are reported as restricted cash and investments on the Consolidated Balance Sheets. The interest income earned on these unremitted funds, where allowed by state law, is reported as investment income in the Consolidated Statement of Income. In other circumstances, the insurance companies collect the premiums directly from the insureds and remit the applicable commissions to Brown & Brown. Accordingly, as reported in the Consolidated Balance Sheets, “commissions” are receivables from insurance companies. “Fees” are primarily receivables due from customers. Investments Certificates of deposit, and other securities, having maturities of more than three months when purchased are reported at cost and are adjusted for other-than-temporary market value declines. The Company’s investment holdings include U.S. Government securities, municipal bonds, domestic corporate and foreign corporate bonds as well as short-duration fixed income funds. Investments within the portfolio or funds are held as available for sale and are carried at their fair value. Any gain/loss applicable from the fair value change is recorded, net of tax, as other comprehensive income within the equity section of the Consolidated Balance Sheet. Realized gains and losses are reported on the Consolidated Statement of Income, with the cost of securities sold determined on a specific identification basis. Fixed Assets Fixed assets, including leasehold improvements, are carried at cost, less accumulated depreciation and amortization. Expenditures for improvements are capitalized, and expenditures for maintenance and repairs are expensed to operations as incurred. Upon sale or retirement, the cost and related accumulated depreciation and amortization are removed from the accounts and the resulting gain or loss, if any, is reflected in other income. Depreciation has been determined using the straight-line method over the estimated useful lives of the related assets, which range from 3 to 15 years. Leasehold improvements are amortized on the straight-line method over the shorter of the useful life of the improvement or the term of the related lease. Goodwill and Amortizable Intangible Assets All of our business combinations initiated after June 30, 2001 are accounted for using the acquisition method. Acquisition purchase prices are typically based upon a multiple of average annual operating profit earned over a period of 3 years within a minimum and maximum price range. The recorded purchase prices for all acquisitions consummated after January 1, 2009 include an estimation of the fair value of liabilities associated with any potential earn-out provisions. Subsequent changes in the fair value of earn-out obligations are recorded in the Consolidated Statement of Income when incurred. The fair value of earn-out obligations is based upon the present value of the expected future payments to be made to the sellers of the acquired businesses in accordance with the provisions contained in the respective purchase agreements. In determining fair value, the acquired business’ future performance is estimated using financial projections developed by management for the acquired business and this estimate reflects market participant assumptions regarding revenue growth and/or profitability. The expected future payments are estimated on the basis of the earn-out formula and performance targets specified in each purchase agreement compared to the associated financial projections. These estimates are then discounted to present value using a risk-adjusted rate that takes into consideration the likelihood that the forecasted earn-out payments will be made. Amortizable intangible assets are stated at cost, less accumulated amortization, and consist of purchased customer accounts and non-compete agreements. Purchased customer accounts and non-compete agreements are amortized on a straight-line basis over the related estimated lives and contract periods, which range from 3 to 15 years. Purchased customer accounts primarily consist of records and files that contain information about insurance policies and the related insured parties that are essential to policy renewals. The excess of the purchase price of an acquisition over the fair value of the identifiable tangible and amortizable intangible assets is assigned to goodwill. While goodwill is not amortizable, it is subject to assessment at least annually, and more frequently in the presence of certain circumstances, for impairment by application of a fair value-based test. The Company compares the fair value of each reporting unit with its carrying amount to determine if there is potential impairment of goodwill. If the fair value of the reporting unit is less than its carrying value, an impairment loss is recorded to the extent that the fair value of the goodwill within the reporting unit is less than its carrying value. Fair value is estimated based upon multiples of earnings before interest, income taxes, depreciation, amortization and change in estimated acquisition earn-out payables (“EBITDAC”), or on a discounted cash flow basis. Brown & Brown completed its most recent annual assessment as of November 30, 2017 and determined that the fair value of goodwill significantly exceeded the carrying value of such assets. In addition, as of December 31, 2017, there are no accumulated impairment losses. The carrying value of amortizable intangible assets attributable to each business or asset group comprising Brown & Brown is periodically reviewed by management to determine if there are events or changes in circumstances that would indicate that its carrying amount may not be recoverable. Accordingly, if there are any such changes in circumstances during the year, Brown & Brown assesses the carrying value of its amortizable intangible assets by considering the estimated future undiscounted cash flows generated by the corresponding business or asset group. Any impairment identified through this assessment may require that the carrying value of related amortizable intangible assets be adjusted. There were no impairments recorded for the years ended December 31, 2017, 2016 and 2015. Income Taxes Brown & Brown records income tax expense using the asset-and-liability method of accounting for deferred income taxes. Under this method, deferred tax assets and liabilities are recognized for the expected future tax consequences of temporary differences between the financial statement carrying values and the income tax bases of Brown & Brown’s assets and liabilities. Brown & Brown files a consolidated federal income tax return and has elected to file consolidated returns in certain states. Deferred income taxes are provided for in the Consolidated Financial Statements and relate principally to expenses charged to income for financial reporting purposes in one period and deducted for income tax purposes in other periods.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In November 2016, the Financial Accountings Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-18, “Statement of Cash Flows (Topic 230)”: Restricted Cash (“ASU 2016-18”), which requires that the Statement of Cash Flows explain the changes during the period of cash and cash equivalents inclusive of amounts categorized as restricted cash. ASU 2016-18 is effective for periods beginning after December 15, 2017. However, the Company elected to early adopt for the reporting period beginning January 1, 2017 under the full retrospective approach for all periods presented. With the adoption of ASU 2016-18, the change in restricted cash is no longer reflected as a change in operating assets and liabilities, and the Statement of Cash Flows details the changes in the balance of cash and cash equivalents inclusive of restricted cash. Net cash provided by operating activities for the years ended December 31, 2015 and 2016 were previously reported as $411.8 million and $375.2 million, respectively. With the retrospective adoption, the net cash provided by operating activities for the years ended December 31, 2015 and 2016 is now reported as $381.8 million and $411.0 million, respectively. The Company reflects cash collected from customers that is payable to insurance companies as restricted cash if segregation of this cash is required by the state of domicile for the office conducting this transaction or if required by contract with the relevant insurance company providing coverage. Cash collected from customers that is payable to insurance companies is reported in cash and cash equivalents if no such restriction is required. In August 2016, the FASB issued ASU 2016-15, “Statement of Cash Flows (Topic 230)”: Classification of Certain Cash Receipts and Cash Payments (a consensus of the Emerging Issues Task Force) (“ASU 2016-15”), which addresses eight specific cash flow issues with the objective of reducing the existing diversity in practice in how certain cash receipts and cash payments are presented and classified and applies to all entities, including both business entities and not-for-profit entities that are required to present a statement of cash flows under Topic 230. ASU 2016-15 will take effect for public companies for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2017 and early adoption is permitted. The Company is adopting this change effective January 1, 2018 and has evaluated the impact of ASU 2016-15 determining that there is no impact on the Company’s Statement of Cash Flows. The Company already presents cash paid on contingent consideration in business combination as prescribed by ASU 2016-15 and does not, at this time, engage in the other activities being addressed. In March 2016, the FASB issued ASU 2016-09, “Improvements to Employee Share Based Payment Accounting” (“ASU 2016-09”), which amends guidance issued in Accounting Standards Codification (“ASC”) Topic 718, Compensation - Stock Compensation. ASU 2016-09 simplifies several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. ASU 2016-09 is effective for fiscal years beginning after December 15, 2016, and interim periods within those fiscal years and early adoption is permitted. The Company adopted the guidance on January 1, 2017, as required. Prior periods have not been adjusted, as the guidance was adopted prospectively. The principal impact is that the tax benefit or expense from stock compensation is now presented in the income tax line of the Statement of Income, whereas the prior treatment was to present this amount as a component of equity on the Balance Sheet. In addition, the tax benefit or expense is now presented as activity in Cash Flow from Operating Activity, rather than the prior presentation as Cash Flow from Financing Activity in the Statement of Cash Flows. The Company also continues to estimate forfeitures of stock grants as allowed by ASU 2016-09. In March 2016, the FASB issued ASU 2016-08, “Principal Versus Agent Considerations (Reporting Revenue Gross Versus Net)” (“ASU 2016-08”) to clarify certain aspects of the principal-versus-agent guidance included in the new revenue standard ASU 2014-09 “Revenue from Contracts with Customers” (“ASU 2014-09”). The FASB issued the ASU in response to concerns identified by stakeholders, including those related to (1) determining the appropriate unit of account under the revenue standard’s principal-versus-agent guidance and (2) applying the indicators of whether an entity is a principal or an agent in accordance with the revenue standard’s control principle. ASU 2016-08 is effective contemporaneous with ASU 2014-09 beginning January 1, 2018. The impact of adopting ASU 2016-08 is not material to the Company. In February 2016, the FASB issued ASU 2016-02, “Leases (Topic 842)” (“ASU 2016-02”), which provides guidance for accounting for leases. Under ASU 2016-02, the Company will be required to recognize the assets and liabilities for the rights and obligations created by leased assets. ASU 2016-02 will take effect for public companies for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. The Company continues to evaluate the impact of this pronouncement with the principal impact being that the present value of the remaining lease payments be presented as a liability on the Balance Sheet as well as an asset of similar value representing the “Right of Use” for those leased properties. As detailed in Note 13 of the 2016 10-K, the undiscounted contractual cash payments remaining on leased properties was $213.2 million as of December 31, 2016 and is $210.4 million as of December 31, 2017 as detailed in “Management’s Discussion and Analysis of Financial Condition and Results of Operations - Liquidity and Capital Resources” and Note 13 “Commitments and Contingencies.” In November 2015, FASB issued ASU No. 2015-17, “Income Taxes (Topic 740) - Balance Sheet Classification of Deferred Taxes” (“ASU 2015-17”), which simplifies the presentation of deferred income taxes by requiring deferred tax assets and liabilities be classified as a single non-current item on the balance sheet. ASU 2015-17 is effective for fiscal years beginning after December 15, 2016 with early adoption permitted as of the beginning of any interim or annual reporting period. The Company adopted the guidance on January 1, 2017, as required. As a result, the Company retrospectively applied the guidance to the 2016 balance sheet by reclassifying $24.6 million from deferred income taxes (asset) to deferred income taxes, net (liability) on the Condensed Consolidated Balance Sheet. This reclassification occurred prior to the passage of the Tax Cuts and Jobs Act of 2017, which had a material impact on the value of deferred tax items. See Note 9 “Income Taxes” for more information. In May 2014, FASB issued ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606)” (“Topic 606”), which provides guidance for revenue recognition. Topic 606 affects any entity that either enters into contracts with customers to transfer goods or services or enters into contracts for the transfer of non-financial assets. It supersedes the revenue recognition requirements in Topic 605, “Revenue Recognition,” and most industry-specific guidance. The standard’s core principle is that a company should recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which a company expects to be entitled in exchange for those goods or services. In doing so, companies will need to use more judgment and make more estimates than under the current guidance. Specifically, in situations where multiple performance obligations exist within a contract, the use of estimates is required to allocate the transaction price to each separate performance obligation. Historically, approximately 70% of the Company’s commissions and fees are in the form of commissions paid by insurance carriers. These commissions are earned upon the effective date of bound coverage, as no significant performance obligation remains after coverage is bound. The following areas are impacted by the adoption of Topic 606: Installment billing - Prior to the adoption of Topic 606, commission revenues related to installment billings were recognized on the latter of the policy effective date (as indicated in the policy) or the date that the premium was billed to the client (as indicated on the premium invoice), with the exception of our Arrowhead businesses, which follow a policy of recognizing these revenues on the latter of the policy effective date or processed date into our systems, regardless of the billing arrangement. As a result of the adoption of Topic 606, revenue associated with the issuance of policies will be recognized upon the effective date of the associated policy, which means that commission revenues billed on an installment basis will be now recognized earlier than they had been previously resulting in revenue will accrued based upon the completion of the performance obligation and thus creating a current asset for the unbilled revenue until such time as an invoice is generated, typically not to exceed twelve months. The Company does not expect the overall impact of these changes to be significant on a full-year basis, but the timing of recognizing revenue will be impacted among quarters when compared to prior years. Contingent commissions - Prior to the adoption of Topic 606, revenue that was not fixed and determinable because a contingency exists was not recognized until the contingency was resolved. Under Topic 606, the Company must use its judgment to estimate the amount of consideration that will be received such that a significant reversal of revenue is not probable. Contingent commissions represent a form of variable consideration associated with the same performance obligation, which is the placement of coverage, for which we earn core commissions. In connection with the new standard, contingent commissions will be estimated with an appropriate constraint applied and accrued relative to the recognition of the corresponding core commissions. The resulting effect on the timing of recognition of contingent commissions will more closely follow a similar pattern as our core commissions with true-ups recognized when payments are received or as additional information that affects the estimate becomes available. Contingent commissions have averaged approximately 3.6% of the previous year’s total commissions and fees over the last three years and have primarily been received in the first and second quarters of the year. Approximately 30% of the Company’s commissions and fees is in the form of fees, which are predominantly in our National Programs and Services Segments, and to a lesser extent in the large accounts business within our Retail Segment, where we receive fees in lieu of a commission. In accordance with Topic 606, fee revenue from certain agreements will be recognized in earlier periods and others in later periods as compared to our current accounting treatment. The Company does not expect the overall impact of these changes to be significant on a full-year basis, but the timing of recognizing revenue will be impacted among quarters when compared to prior years. Additionally, the Company has evaluated ASC Topic 340 - Other Assets and Deferred Cost (“ASC 340”) which requires companies to defer certain incremental costs to obtain customer contracts, and certain costs to fulfill customer contracts. Incremental cost to obtain - the adoption of ASC 340 will result in the Company deferring certain cost to obtain customer contracts primarily as they relate to commission based compensation plans in the Retail Segment, in which the Company pays an incremental amount of compensation on new business in the first year of the contract. These incremental costs will be deferred and amortized over a 15-year period, which is consistent with the analysis performed on acquired customer accounts and referenced in Note 4 to the Company’s financial statements. Cost to fulfill - the adoption of ASC 340 will result in the Company deferring certain costs to fulfill a contract and recognize these costs as the associated performance obligations are fulfilled. In order for contract fulfillment costs to be deferred under ASC 340, the costs must (1) relate directly to a specific contract or anticipated contract, (2) generate or enhance resources that the Company will use in satisfying its obligations under the contract, and (3) be expected to be recovered through sufficient net cash flows from the contract. The Company does not expect the overall impact of these changes to be significant on a full-year basis, but the timing of recognizing these expenses will be impacted among quarters to better align with the associated revenue. Topic 606 is effective for the Company beginning January 1, 2018. Entities are permitted to adopt the guidance under one of the following methods: the “full retrospective” method, which applies the guidance to each period presented (prior years restated), or the “modified retrospective” method, in which the guidance is only applied to the year of adoption, with the cumulative effect of initially applying the guidance recognized as an adjustment to retained earnings. The Company has elected to follow the modified retrospective method applied to contracts that are not completed as of the date of adoption. The estimated cumulative impact of adopting the standard on January 1, 2018 is an increase in stockholders’ equity of between $70.0 million and $110.0 million. In connection with the implementation of this standard, we expect to modify, and in some instances institute additional accounting procedures, processes and internal controls. Given the relative expected impacts of this standard to our revenue streams, we do not expect that these modifications and additions will materially change our internal controls over financial reporting.
Consolidation, Policy [Policy Text Block]	Principles of Consolidation The accompanying Consolidated Financial Statements include the accounts of Brown & Brown, Inc. and its subsidiaries. All significant intercompany account balances and transactions have been eliminated in the Consolidated Financial Statements. Segment results for prior periods have been recast, where appropriate, to reflect the current year segmental structure. Certain reclassifications have been made to the prior year amounts reported in this Annual Report on Form 10-K in order to conform to the current year presentation.
Revenue Recognition, Policy [Policy Text Block]	Revenue Recognition Commission revenues are recognized as of the effective date of the insurance policy or the date on which the policy premium is processed into our systems and invoiced to the customer, whichever is later. Commission revenues related to installment billings are recognized on the latter of effective or invoiced date, with the exception of our Arrowhead business which follows a policy of recognizing on the latter of effective or processed date into our systems, regardless of the billing arrangement. Management determines the policy cancellation reserve based upon historical cancellation experience adjusted for any known circumstances. Subsequent commission adjustments were recognized upon our receipt of notification from insurance companies concerning matters necessitating such adjustments. Profit-sharing contingent commissions are recognized when determinable, which is generally when such commissions are received from insurance companies, or when we receive formal notification of the amount of such payments. Fee revenues and commissions for workers’ compensation programs are recognized as services are rendered.
Use of Estimates, Policy [Policy Text Block]	Use of Estimates The preparation of the Consolidated Financial Statements in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, as well as disclosures of contingent assets and liabilities, at the date of the Consolidated Financial Statements, and the reported amounts of revenues and expenses during the reporting period. Actual results may differ from those estimates
Cash and Cash Equivalents, Policy [Policy Text Block]	Cash and Cash Equivalents Cash and cash equivalents principally consist of demand deposits with financial institutions and highly liquid investments with quoted market prices having maturities of three months or less when purchased.
Restricted Cash and Investments Premiums Commissions and Fees Receivable Policy [Text Block]	Restricted Cash and Investments, and Premiums, Commissions and Fees Receivable In our capacity as an insurance agent or broker, the Company typically collects premiums from insureds and, after deducting the authorized commissions, remits the net premiums to the appropriate insurance company or companies. Accordingly, as reported in the Consolidated Balance Sheets, “premiums” are receivable from insureds. Unremitted net insurance premiums are held in a fiduciary capacity until Brown & Brown disburses them. Where allowed by law, Brown & Brown invests these unremitted funds only in cash, money market accounts, tax-free variable-rate demand bonds and commercial paper held for a short term. In certain states in which Brown & Brown operates, the use and investment alternatives for these funds are regulated and restricted by various state laws and agencies. These restricted funds are reported as restricted cash and investments on the Consolidated Balance Sheets. The interest income earned on these unremitted funds, where allowed by state law, is reported as investment income in the Consolidated Statement of Income. In other circumstances, the insurance companies collect the premiums directly from the insureds and remit the applicable commissions to Brown & Brown. Accordingly, as reported in the Consolidated Balance Sheets, “commissions” are receivables from insurance companies. “Fees” are primarily receivables due from customers.
Investment, Policy [Policy Text Block]	Investments Certificates of deposit, and other securities, having maturities of more than three months when purchased are reported at cost and are adjusted for other-than-temporary market value declines. The Company’s investment holdings include U.S. Government securities, municipal bonds, domestic corporate and foreign corporate bonds as well as short-duration fixed income funds. Investments within the portfolio or funds are held as available for sale and are carried at their fair value. Any gain/loss applicable from the fair value change is recorded, net of tax, as other comprehensive income within the equity section of the Consolidated Balance Sheet. Realized gains and losses are reported on the Consolidated Statement of Income, with the cost of securities sold determined on a specific identification basis
Property, Plant and Equipment, Policy [Policy Text Block]	Fixed Assets Fixed assets, including leasehold improvements, are carried at cost, less accumulated depreciation and amortization. Expenditures for improvements are capitalized, and expenditures for maintenance and repairs are expensed to operations as incurred. Upon sale or retirement, the cost and related accumulated depreciation and amortization are removed from the accounts and the resulting gain or loss, if any, is reflected in other income. Depreciation has been determined using the straight-line method over the estimated useful lives of the related assets, which range from 3 to 15 years. Leasehold improvements are amortized on the straight-line method over the shorter of the useful life of the improvement or the term of the related lease.
Goodwill and Intangible Assets, Intangible Assets, Policy [Policy Text Block]	Goodwill and Amortizable Intangible Assets All of our business combinations initiated after June 30, 2001 are accounted for using the acquisition method. Acquisition purchase prices are typically based upon a multiple of average annual operating profit earned over a period of 3 years within a minimum and maximum price range. The recorded purchase prices for all acquisitions consummated after January 1, 2009 include an estimation of the fair value of liabilities associated with any potential earn-out provisions. Subsequent changes in the fair value of earn-out obligations are recorded in the Consolidated Statement of Income when incurred. The fair value of earn-out obligations is based upon the present value of the expected future payments to be made to the sellers of the acquired businesses in accordance with the provisions contained in the respective purchase agreements. In determining fair value, the acquired business’ future performance is estimated using financial projections developed by management for the acquired business and this estimate reflects market participant assumptions regarding revenue growth and/or profitability. The expected future payments are estimated on the basis of the earn-out formula and performance targets specified in each purchase agreement compared to the associated financial projections. These estimates are then discounted to present value using a risk-adjusted rate that takes into consideration the likelihood that the forecasted earn-out payments will be made. Amortizable intangible assets are stated at cost, less accumulated amortization, and consist of purchased customer accounts and non-compete agreements. Purchased customer accounts and non-compete agreements are amortized on a straight-line basis over the related estimated lives and contract periods, which range from 3 to 15 years. Purchased customer accounts primarily consist of records and files that contain information about insurance policies and the related insured parties that are essential to policy renewals. The excess of the purchase price of an acquisition over the fair value of the identifiable tangible and amortizable intangible assets is assigned to goodwill. While goodwill is not amortizable, it is subject to assessment at least annually, and more frequently in the presence of certain circumstances, for impairment by application of a fair value-based test. The Company compares the fair value of each reporting unit with its carrying amount to determine if there is potential impairment of goodwill. If the fair value of the reporting unit is less than its carrying value, an impairment loss is recorded to the extent that the fair value of the goodwill within the reporting unit is less than its carrying value. Fair value is estimated based upon multiples of earnings before interest, income taxes, depreciation, amortization and change in estimated acquisition earn-out payables (“EBITDAC”), or on a discounted cash flow basis. Brown & Brown completed its most recent annual assessment as of November 30, 2017 and determined that the fair value of goodwill significantly exceeded the carrying value of such assets. In addition, as of December 31, 2017, there are no accumulated impairment losses. The carrying value of amortizable intangible assets attributable to each business or asset group comprising Brown & Brown is periodically reviewed by management to determine if there are events or changes in circumstances that would indicate that its carrying amount may not be recoverable. Accordingly, if there are any such changes in circumstances during the year, Brown & Brown assesses the carrying value of its amortizable intangible assets by considering the estimated future undiscounted cash flows generated by the corresponding business or asset group. Any impairment identified through this assessment may require that the carrying value of related amortizable intangible assets be adjusted. There were no impairments recorded for the years ended December 31, 2017, 2016 and 2015.
Income Tax, Policy [Policy Text Block]	Income Taxes Brown & Brown records income tax expense using the asset-and-liability method of accounting for deferred income taxes. Under this method, deferred tax assets and liabilities are recognized for the expected future tax consequences of temporary differences between the financial statement carrying values and the income tax bases of Brown & Brown’s assets and liabilities. Brown & Brown files a consolidated federal income tax return and has elected to file consolidated returns in certain states. Deferred income taxes are provided for in the Consolidated Financial Statements and relate principally to expenses charged to income for financial reporting purposes in one period and deducted for income tax purposes in other periods.
Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block]	Stock-Based Compensation The Company has granted stock options and grants non-vested stock awards to its employees and officers and fully vested stock awards to directors. The Company uses the modified-prospective method to account for share-based payments. Under the modified-prospective method, compensation cost is recognized for all share-based payments granted on or after January 1, 2006 and for all awards granted to employees prior to January 1, 2006 that remained unvested on that date. The Company uses the alternative-transition method to account for the income tax effects of payments made related to stock-based compensation. The Company uses the Black-Scholes valuation model for valuing all stock options and shares purchased under the Employee Stock Purchase Plan (the “ESPP”). Compensation for non-vested stock awards is measured at fair value on the grant date based upon the number of shares expected to vest. Compensation cost for all awards is recognized in earnings, net of estimated forfeitures, on a straight-line basis over the requisite service period
Reinsurance Accounting Policy [Policy Text Block]	Reinsurance The Company protects itself from claims-related losses by reinsuring all claims risk exposure. The only line of insurance the Company underwrites is flood insurance associated with the Wright National Flood Insurance Company (“WNFIC”), which is part of our National Programs Segment. However, all exposure is reinsured with the Federal Emergency Management Agency (“FEMA”) for basic admitted policies conforming to the National Flood Insurance Program. For excess flood insurance policies, all exposure is reinsured with a reinsurance carrier with an AM Best Company rating of “A” or better. Reinsurance does not legally discharge the ceding insurer from the primary liability for the full amount due under the reinsured policies. Reinsurance premiums, commissions, expense reimbursement and reserves related to ceded business are accounted for on a basis consistent with the accounting for the original policies issued and the terms of reinsurance contracts. Premiums earned and losses and loss adjustment expenses incurred are reported net of reinsurance amounts. Other underwriting expenses are shown net of earned ceding commission income. The liabilities for unpaid losses and loss adjustment expenses and unearned premiums are reported gross of ceded reinsurance recoverable. Balances due from reinsurers on unpaid losses and loss adjustment expenses, including an estimate of such recoverables related to reserves for incurred but not reported (“IBNR”) losses, are reported as assets and are included in reinsurance recoverable even though amounts due on unpaid loss and loss adjustment expense are not recoverable from the reinsurer until such losses are paid. The Company does not believe it is exposed to any material credit risk through its reinsurance as the reinsurer is FEMA for basic admitted flood policies and a national reinsurance carrier for excess flood policies, which has an AM Best Company rating of “A” or better. Historically, no amounts due from reinsurance carriers have been written off as uncollectible.
Unpaid Policy Claims and Claims Adjustment Expense, Policy [Policy Text Block]	Unpaid Losses and Loss Adjustment Reserve Unpaid losses and loss adjustment reserve include amounts determined on individual claims and other estimates based upon the past experience of WNFIC and the policyholders for IBNR claims, less anticipated salvage and subrogation recoverable. The methods of making such estimates and for establishing the resulting reserves are continually reviewed and updated, and any adjustments resulting therefrom are reflected in operations currently. WNFIC engages the services of outside actuarial consulting firms (the “Actuaries”) to assist on an annual basis to render an opinion on the sufficiency of the Company’s estimates for unpaid losses and related loss adjustment reserve. The Actuaries utilize both industry experience and the Company’s own experience to develop estimates of those amounts as of year-end. These estimated liabilities are subject to the impact of future changes in claim severity, frequency and other factors. In spite of the variability inherent in such estimates, management believes that the liabilities for unpaid losses and related loss adjustment reserve are adequate.
Insurance Premiums Revenue Recognition, Policy [Policy Text Block]	PremiumsPremiums are recognized as income over the coverage period of the related policies. Unearned premiums represent the portion of premiums written that relate to the unexpired terms of the policies in force and are determined on a daily pro rata basis. The income is recorded to the commissions and fees line of the income statement.
Minimum
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Maximum
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	15 years

Nature of Operations (Policies)	12 Months Ended
Nature of Operations (Policies)	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Operations	Nature of OperationsBrown & Brown, Inc., a Florida corporation, and its subsidiaries (collectively, “Brown & Brown” or the “Company”) is a diversified insurance agency, wholesale brokerage, insurance programs and services organization that markets and sells to its customers, insurance products and services, primarily in the property, casualty and employee benefits areas. Brown & Brown’s business is divided into four reportable segments: the Retail Segment provides a broad range of insurance products and services to commercial, public and quasi-public entities, professional and individual customers; the National Programs Segment, acting as a managing general agent (“MGA”), provides professional liability and related package products for certain professionals, a range of insurance products for individuals, flood coverage, and targeted products and services designated for specific industries, trade groups, governmental entities and market niches, all of which are delivered through nationwide networks of independent agents, including Brown & Brown retail agents; the Wholesale Brokerage Segment markets and sells excess and surplus commercial insurance, primarily through independent agents and brokers, as well as Brown & Brown Retail offices; and the Services Segment provides insurance-related services, including third-party claims administration and comprehensive medical utilization management services in both the workers’ compensation and all-lines liability arenas, as well as Medicare Set-aside services, Social Security disability and Medicare benefits advocacy services, and claims adjusting services.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In November 2016, the Financial Accountings Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-18, “Statement of Cash Flows (Topic 230)”: Restricted Cash (“ASU 2016-18”), which requires that the Statement of Cash Flows explain the changes during the period of cash and cash equivalents inclusive of amounts categorized as restricted cash. ASU 2016-18 is effective for periods beginning after December 15, 2017. However, the Company elected to early adopt for the reporting period beginning January 1, 2017 under the full retrospective approach for all periods presented. With the adoption of ASU 2016-18, the change in restricted cash is no longer reflected as a change in operating assets and liabilities, and the Statement of Cash Flows details the changes in the balance of cash and cash equivalents inclusive of restricted cash. Net cash provided by operating activities for the years ended December 31, 2015 and 2016 were previously reported as $411.8 million and $375.2 million, respectively. With the retrospective adoption, the net cash provided by operating activities for the years ended December 31, 2015 and 2016 is now reported as $381.8 million and $411.0 million, respectively. The Company reflects cash collected from customers that is payable to insurance companies as restricted cash if segregation of this cash is required by the state of domicile for the office conducting this transaction or if required by contract with the relevant insurance company providing coverage. Cash collected from customers that is payable to insurance companies is reported in cash and cash equivalents if no such restriction is required. In August 2016, the FASB issued ASU 2016-15, “Statement of Cash Flows (Topic 230)”: Classification of Certain Cash Receipts and Cash Payments (a consensus of the Emerging Issues Task Force) (“ASU 2016-15”), which addresses eight specific cash flow issues with the objective of reducing the existing diversity in practice in how certain cash receipts and cash payments are presented and classified and applies to all entities, including both business entities and not-for-profit entities that are required to present a statement of cash flows under Topic 230. ASU 2016-15 will take effect for public companies for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2017 and early adoption is permitted. The Company is adopting this change effective January 1, 2018 and has evaluated the impact of ASU 2016-15 determining that there is no impact on the Company’s Statement of Cash Flows. The Company already presents cash paid on contingent consideration in business combination as prescribed by ASU 2016-15 and does not, at this time, engage in the other activities being addressed. In March 2016, the FASB issued ASU 2016-09, “Improvements to Employee Share Based Payment Accounting” (“ASU 2016-09”), which amends guidance issued in Accounting Standards Codification (“ASC”) Topic 718, Compensation - Stock Compensation. ASU 2016-09 simplifies several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. ASU 2016-09 is effective for fiscal years beginning after December 15, 2016, and interim periods within those fiscal years and early adoption is permitted. The Company adopted the guidance on January 1, 2017, as required. Prior periods have not been adjusted, as the guidance was adopted prospectively. The principal impact is that the tax benefit or expense from stock compensation is now presented in the income tax line of the Statement of Income, whereas the prior treatment was to present this amount as a component of equity on the Balance Sheet. In addition, the tax benefit or expense is now presented as activity in Cash Flow from Operating Activity, rather than the prior presentation as Cash Flow from Financing Activity in the Statement of Cash Flows. The Company also continues to estimate forfeitures of stock grants as allowed by ASU 2016-09. In March 2016, the FASB issued ASU 2016-08, “Principal Versus Agent Considerations (Reporting Revenue Gross Versus Net)” (“ASU 2016-08”) to clarify certain aspects of the principal-versus-agent guidance included in the new revenue standard ASU 2014-09 “Revenue from Contracts with Customers” (“ASU 2014-09”). The FASB issued the ASU in response to concerns identified by stakeholders, including those related to (1) determining the appropriate unit of account under the revenue standard’s principal-versus-agent guidance and (2) applying the indicators of whether an entity is a principal or an agent in accordance with the revenue standard’s control principle. ASU 2016-08 is effective contemporaneous with ASU 2014-09 beginning January 1, 2018. The impact of adopting ASU 2016-08 is not material to the Company. In February 2016, the FASB issued ASU 2016-02, “Leases (Topic 842)” (“ASU 2016-02”), which provides guidance for accounting for leases. Under ASU 2016-02, the Company will be required to recognize the assets and liabilities for the rights and obligations created by leased assets. ASU 2016-02 will take effect for public companies for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. The Company continues to evaluate the impact of this pronouncement with the principal impact being that the present value of the remaining lease payments be presented as a liability on the Balance Sheet as well as an asset of similar value representing the “Right of Use” for those leased properties. As detailed in Note 13 of the 2016 10-K, the undiscounted contractual cash payments remaining on leased properties was $213.2 million as of December 31, 2016 and is $210.4 million as of December 31, 2017 as detailed in “Management’s Discussion and Analysis of Financial Condition and Results of Operations - Liquidity and Capital Resources” and Note 13 “Commitments and Contingencies.” In November 2015, FASB issued ASU No. 2015-17, “Income Taxes (Topic 740) - Balance Sheet Classification of Deferred Taxes” (“ASU 2015-17”), which simplifies the presentation of deferred income taxes by requiring deferred tax assets and liabilities be classified as a single non-current item on the balance sheet. ASU 2015-17 is effective for fiscal years beginning after December 15, 2016 with early adoption permitted as of the beginning of any interim or annual reporting period. The Company adopted the guidance on January 1, 2017, as required. As a result, the Company retrospectively applied the guidance to the 2016 balance sheet by reclassifying $24.6 million from deferred income taxes (asset) to deferred income taxes, net (liability) on the Condensed Consolidated Balance Sheet. This reclassification occurred prior to the passage of the Tax Cuts and Jobs Act of 2017, which had a material impact on the value of deferred tax items. See Note 9 “Income Taxes” for more information. In May 2014, FASB issued ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606)” (“Topic 606”), which provides guidance for revenue recognition. Topic 606 affects any entity that either enters into contracts with customers to transfer goods or services or enters into contracts for the transfer of non-financial assets. It supersedes the revenue recognition requirements in Topic 605, “Revenue Recognition,” and most industry-specific guidance. The standard’s core principle is that a company should recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which a company expects to be entitled in exchange for those goods or services. In doing so, companies will need to use more judgment and make more estimates than under the current guidance. Specifically, in situations where multiple performance obligations exist within a contract, the use of estimates is required to allocate the transaction price to each separate performance obligation. Historically, approximately 70% of the Company’s commissions and fees are in the form of commissions paid by insurance carriers. These commissions are earned upon the effective date of bound coverage, as no significant performance obligation remains after coverage is bound. The following areas are impacted by the adoption of Topic 606: Installment billing - Prior to the adoption of Topic 606, commission revenues related to installment billings were recognized on the latter of the policy effective date (as indicated in the policy) or the date that the premium was billed to the client (as indicated on the premium invoice), with the exception of our Arrowhead businesses, which follow a policy of recognizing these revenues on the latter of the policy effective date or processed date into our systems, regardless of the billing arrangement. As a result of the adoption of Topic 606, revenue associated with the issuance of policies will be recognized upon the effective date of the associated policy, which means that commission revenues billed on an installment basis will be now recognized earlier than they had been previously resulting in revenue will accrued based upon the completion of the performance obligation and thus creating a current asset for the unbilled revenue until such time as an invoice is generated, typically not to exceed twelve months. The Company does not expect the overall impact of these changes to be significant on a full-year basis, but the timing of recognizing revenue will be impacted among quarters when compared to prior years. Contingent commissions - Prior to the adoption of Topic 606, revenue that was not fixed and determinable because a contingency exists was not recognized until the contingency was resolved. Under Topic 606, the Company must use its judgment to estimate the amount of consideration that will be received such that a significant reversal of revenue is not probable. Contingent commissions represent a form of variable consideration associated with the same performance obligation, which is the placement of coverage, for which we earn core commissions. In connection with the new standard, contingent commissions will be estimated with an appropriate constraint applied and accrued relative to the recognition of the corresponding core commissions. The resulting effect on the timing of recognition of contingent commissions will more closely follow a similar pattern as our core commissions with true-ups recognized when payments are received or as additional information that affects the estimate becomes available. Contingent commissions have averaged approximately 3.6% of the previous year’s total commissions and fees over the last three years and have primarily been received in the first and second quarters of the year. Approximately 30% of the Company’s commissions and fees is in the form of fees, which are predominantly in our National Programs and Services Segments, and to a lesser extent in the large accounts business within our Retail Segment, where we receive fees in lieu of a commission. In accordance with Topic 606, fee revenue from certain agreements will be recognized in earlier periods and others in later periods as compared to our current accounting treatment. The Company does not expect the overall impact of these changes to be significant on a full-year basis, but the timing of recognizing revenue will be impacted among quarters when compared to prior years. Additionally, the Company has evaluated ASC Topic 340 - Other Assets and Deferred Cost (“ASC 340”) which requires companies to defer certain incremental costs to obtain customer contracts, and certain costs to fulfill customer contracts. Incremental cost to obtain - the adoption of ASC 340 will result in the Company deferring certain cost to obtain customer contracts primarily as they relate to commission based compensation plans in the Retail Segment, in which the Company pays an incremental amount of compensation on new business in the first year of the contract. These incremental costs will be deferred and amortized over a 15-year period, which is consistent with the analysis performed on acquired customer accounts and referenced in Note 4 to the Company’s financial statements. Cost to fulfill - the adoption of ASC 340 will result in the Company deferring certain costs to fulfill a contract and recognize these costs as the associated performance obligations are fulfilled. In order for contract fulfillment costs to be deferred under ASC 340, the costs must (1) relate directly to a specific contract or anticipated contract, (2) generate or enhance resources that the Company will use in satisfying its obligations under the contract, and (3) be expected to be recovered through sufficient net cash flows from the contract. The Company does not expect the overall impact of these changes to be significant on a full-year basis, but the timing of recognizing these expenses will be impacted among quarters to better align with the associated revenue. Topic 606 is effective for the Company beginning January 1, 2018. Entities are permitted to adopt the guidance under one of the following methods: the “full retrospective” method, which applies the guidance to each period presented (prior years restated), or the “modified retrospective” method, in which the guidance is only applied to the year of adoption, with the cumulative effect of initially applying the guidance recognized as an adjustment to retained earnings. The Company has elected to follow the modified retrospective method applied to contracts that are not completed as of the date of adoption. The estimated cumulative impact of adopting the standard on January 1, 2018 is an increase in stockholders’ equity of between $70.0 million and $110.0 million. In connection with the implementation of this standard, we expect to modify, and in some instances institute additional accounting procedures, processes and internal controls. Given the relative expected impacts of this standard to our revenue streams, we do not expect that these modifications and additions will materially change our internal controls over financial reporting.

Net Income Per Share (Tables)

12 Months Ended

Dec. 31, 2017

Earnings Per Share [Abstract]

Reconciliation between Basic and Diluted Weighted Average Shares Outstanding

The following is a reconciliation between basic and diluted weighted-average shares outstanding for the years ended December 31:



(in thousands, except per share data)	2017			2016			2015
Net income	$	399,630		$	257,491		$	243,318
Net income attributable to unvested awarded performance stock	(9,746		)	(6,705		)	(5,695		)
Net income attributable to common shares	$	389,884		$	250,786		$	237,623
Weighted-average number of common shares outstanding – basic	139,697			139,779			141,113
Less unvested awarded performance stock included in weighted-average number of common shares outstanding – basic	(3,407		)	(3,640		)	(3,303		)
Weighted-average number of common shares outstanding for basic earnings per common share	136,290			136,139			137,810
Dilutive effect of stock options	2,503			1,665			2,302
Weighted-average number of shares outstanding – diluted	138,793			137,804			140,112
Net income per share:
Basic	$	2.86		$	1.84		$	1.72
Diluted	$	2.81		$	1.82		$	1.70

Business Combinations (Tables)

12 Months Ended

Dec. 31, 2017

Dec. 31, 2016

Dec. 31, 2015

Business Combinations [Abstract]

Purchase price allocation for current year acquisitions and adjustments made for prior year acquisitions



(in thousands)
Name	Business Segment	Effective Date of Acquisition	Cash Paid		Other Payable		Recorded Earn-Out Payable		Net Assets Acquired		Maximum Potential Earn- Out Payable
Other	Various	Various	$	41,471	$	11,708	$	6,921	$	60,100	$	27,451
Total			$	41,471	$	11,708	$	6,921	$	60,100	$	27,451



(in thousands)
Name	Business Segment	Effective Date of Acquisition	Cash Paid		Note Payable		Other Payable		Recorded Earn-Out Payable		Net Assets Acquired		Maximum Potential Earn- Out Payable
Social Security Advocates for the Disabled LLC (SSAD)	Services	February 1, 2016	$	32,526	$	492	$	—	$	971	$	33,989	$	3,500
Morstan General Agency, Inc. (Morstan)	Wholesale Brokerage	June 1, 2016	66,050		—		10,200		3,091		79,341		5,000
Other	Various	Various	26,140		—		464		400		27,004		7,785
Total			$	124,716	$	492	$	10,664	$	4,462	$	140,334	$	16,285



(in thousands)
Name	Business Segment	Effective Date of Acquisition	Cash Paid		Other Payable		Recorded Earn-Out Payable		Net Assets Acquired		Maximum Potential Earn- Out Payable
Liberty Insurance Brokers, Inc. and Affiliates (Liberty)	Retail	February 1, 2015	$	12,000	$	—	$	2,981	$	14,981	$	3,750
Spain Agency, Inc. (Spain)	Retail	March 1, 2015	20,706		—		2,617		23,323		9,162
Bellingham Underwriters, Inc. (Bellingham)	National Programs	May 1, 2015	9,007		500		3,322		12,829		4,400
Fitness Insurance, LLC (Fitness)	Retail	June 1, 2015	9,455		—		2,379		11,834		3,500
Strategic Benefit Advisors, Inc. (SBA)	Retail	June 1, 2015	49,600		400		13,587		63,587		26,000
Bentrust Financial, Inc. (Bentrust)	Retail	December 1, 2015	10,142		391		319		10,852		2,200
MBA Insurance Agency of Arizona, Inc. (MBA)	Retail	December 1, 2015	68		8,442		6,063		14,573		9,500
Smith Insurance, Inc. (Smith)	Retail	December 1, 2015	12,096		200		1,047		13,343		6,350
Other	Various	Various	12,926		95		4,584		17,605		8,212
Total			$	136,000	$	10,028	$	36,899	$	182,927	$	73,074

Estimated fair values of aggregate assets and liabilities acquired

The following table summarizes the estimated fair values of the aggregate assets and liabilities acquired as of the date of each acquisition.



(in thousands)	Total
Other current assets	$	601
Fixed assets	69
Goodwill	42,172
Purchased customer accounts	18,738
Non-compete agreements	721
Total assets acquired	62,301
Other current liabilities	(1,512		)
Deferred income tax, net	(689		)
Total liabilities assumed	(2,201		)
Net assets acquired	$	60,100

The following table summarizes the estimated fair values of the aggregate assets and liabilities acquired as of the date of each acquisition.



(in thousands)	SSAD			Morstan			Other			Total
Cash	$	2,094		$	—		$	—		$	2,094
Other current assets	1,042			2,482			1,555			5,079
Fixed assets	307			300			77			684
Goodwill	22,352			51,454			19,570			93,376
Purchased customer accounts	13,069			26,481			11,075			50,625
Non-compete agreements	72			39			117			228
Other assets	—			—			20			20
Total assets acquired	38,936			80,756			32,414			152,106
Other current liabilities	(1,717		)	(1,415		)	(5,410		)	(8,542		)
Deferred income tax, net	(3,230		)	—			—			(3,230		)
Total liabilities assumed	(4,947		)	(1,415		)	(5,410		)	(11,772		)
Net assets acquired	$	33,989		$	79,341		$	27,004		$	140,334



(in thousands)	Liberty			Spain			Bellingham			Fitness			SBA		Bentrust			MBA			Smith			Other			Total
Other current assets	$	2,486		$	324		$	—		$	9		$	652	$	—		$	—		$	—		$	169		$	3,640
Fixed assets	40			50			25			17			41		36			33			73			59			374
Goodwill	10,010			15,748			9,608			8,105			39,859		8,166			13,471			10,374			21,040			136,381
Purchased customer accounts	4,506			7,430			3,223			3,715			23,000		2,789			7,338			3,526			(2,135		)	53,392
Non-compete agreements	24			21			21			—			21		43			11			31			156			328
Other assets	—			—			—			—			14		—			—			—			—			14
Total assets acquired	17,066			23,573			12,877			11,846			63,587		11,034			20,853			14,004			19,289			194,129
Other current liabilities	(42		)	(250		)	(48		)	(12		)	—		(182		)	(6,280		)	(504		)	(4,895		)	(12,213		)
Deferred income tax, net	—			—			—			—			—		—			—			—			2,576			2,576
Other liabilities	(2,043		)	—			—			—			—		—			—			(157		)	635			(1,565		)
Total liabilities assumed	(2,085		)	(250		)	(48		)	(12		)	—		(182		)	(6,280		)	(661		)	(1,684		)	(11,202		)
Net assets acquired	$	14,981		$	23,323		$	12,829		$	11,834		$	63,587	$	10,852		$	14,573		$	13,343		$	17,605		$	182,927

Unaudited pro forma results

These unaudited pro forma results are not necessarily indicative of the actual results of operations that would have occurred had the acquisitions actually been made at the beginning of the respective periods.



(UNAUDITED)	For the Year Ended December 31,
(in thousands, except per share data)	2017		2016
Total revenues	$	1,891,701	$	1,784,776
Income before income taxes	$	453,397	$	429,490
Net income	$	401,908	$	261,133
Net income per share:
Basic	$	2.88	$	1.87
Diluted	$	2.83	$	1.85
Weighted-average number of shares outstanding:
Basic	136,290		136,139
Diluted	138,793		137,804



(UNAUDITED)	For the Year Ended December 31,
(in thousands, except per share data)	2016		2015
Total revenues	$	1,789,790	$	1,716,592
Income before income taxes	$	428,194	$	414,911
Net income	$	260,346	$	250,783
Net income per share:
Basic	$	1.86	$	1.78
Diluted	$	1.84	$	1.75
Weighted-average number of shares outstanding:
Basic	136,139		137,810
Diluted	137,804		140,112



(UNAUDITED)	For the Year Ended December 31,
(in thousands, except per share data)	2015
Total revenues	$	1,688,297
Income before income taxes	$	411,497
Net income	$	248,720
Net income per share:
Basic	$	1.76
Diluted	$	1.73
Weighted-average number of shares outstanding:
Basic	137,810
Diluted	140,112

Schedule Of Business Acquisition Estimated Earn Out Payables Table [Text Block]

The resulting additions, payments and net changes, as well as the interest expense accretion on the estimated acquisition earn-out payables, for the years ended December 31, 2017, 2016 and 2015 were as follows:



	For the Year Ended December 31,
(in thousands)	2017			2016			2015
Balance as of the beginning of the period	$	63,821		$	78,387		$	75,283
Additions to estimated acquisition earn-out payables	6,920			4,462			36,899
Payments for estimated acquisition earn-out payables	(43,766		)	(28,213		)	(36,798		)
Subtotal	26,975			54,636			75,384
Net change in earnings from estimated acquisition earn-out payables:
Change in fair value on estimated acquisition earn-out payables	6,874			6,338			13
Interest expense accretion	2,326			2,847			2,990
Net change in earnings from estimated acquisition earn-out payables	9,200			9,185			3,003
Balance as of December 31,	$	36,175		$	63,821		$	78,387

Goodwill (Tables)

12 Months Ended

Dec. 31, 2017

Goodwill and Intangible Assets Disclosure [Abstract]

Changes in Carrying Value of Goodwill by Operating Segment

The changes in the carrying value of goodwill by reportable segment for the years ended December 31, are as follows:



(in thousands)	Retail			National Programs			Wholesale Brokerage		Services		Total
Balance as of January 1, 2016	$	1,345,636		$	901,866		$	226,961	$	112,220	$	2,586,683
Goodwill of acquired businesses	13,117			(1		)	57,908		22,352		93,376
Goodwill of transferred businesses	571			(571		)	—		—		—
Goodwill disposed of relating to sales of businesses	(4,657		)	—			—		—		(4,657		)
Balance as of December 31, 2016	$	1,354,667		$	901,294		$	284,869	$	134,572	$	2,675,402
Goodwill of acquired businesses	33,076			7,178			1,229		689		42,172
Goodwill disposed of relating to sales of businesses	(1,495		)	—			—		—		(1,495		)
Balance as of December 31, 2017	$	1,386,248		$	908,472		$	286,098	$	135,261	$	2,716,079

Amortizable Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2017

Goodwill and Intangible Assets Disclosure [Abstract]

Amortizable Intangible Assets

Amortizable intangible assets at December 31, 2017 and 2016 consisted of the following:



	December 31, 2017								December 31, 2016
(in thousands)	Gross Carrying Value		Accumulated Amortization			Net Carrying Value		Weighted Average Life in Years⁽¹⁾	Gross Carrying Value		Accumulated Amortization			Net Carrying Value		Weighted Average Life in Years⁽¹⁾
Purchased customer accounts	$	1,464,274	$	(824,584	)	$	639,690	15.0	$	1,447,680	$	(741,770	)	$	705,910	15.0
Non-compete agreements	30,287		(28,972		)	1,315		6.8	29,668		(28,124		)	1,544		6.8
Total	$	1,494,561	$	(853,556	)	$	641,005		$	1,477,348	$	(769,894	)	$	707,454

(1)

Weighted-average life calculated as of the date of acquisition.

Investments (Tables)

12 Months Ended

Dec. 31, 2017

Dec. 31, 2016

Investments, Debt and Equity Securities [Abstract]

Schedule of Investments in Fixed Maturity Securities

At December 31, 2017, the Company’s amortized cost and fair values of fixed maturity securities are summarized as follows:



(in thousands)	Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
U.S. Treasury securities, obligations of U.S. Government agencies and Municipalities	$	29,970	$	—	$	(206	)	$	29,764
Corporate debt	1,072		12		—			1,084
Total	$	31,042	$	12	$	(206	)	$	30,848

At December 31, 2016, the Company’s amortized cost and fair values of fixed maturity securities are summarized as follows:



(in thousands)	Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
U.S. Treasury securities, obligations of U.S. Government agencies and Municipalities	$	26,280	$	11	$	(59	)	$	26,232
Corporate debt	2,358		13		(1		)	2,370
Total	$	28,638	$	24	$	(60	)	$	28,602

Summary of Unrealized Loss Position



(in thousands)	Less than 12 Months					12 Months or More					Total
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
U.S. Treasury securities, obligations of U.S. Government agencies and Municipalities	$	17,919	$	(157	)	$	11,845	$	(49	)	$	29,764	$	(206	)
Corporate debt	400		—			—		—			400		—
Total	$	18,319	$	(157	)	$	11,845	$	(49	)	$	30,164	$	(206	)



(in thousands)	Less than 12 Months					12 Months or More				Total
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
U.S. Treasury securities, obligations of U.S. Government agencies and Municipalities	$	14,663	$	(59	)	$	—	$	—	$	14,663	$	(59	)
Corporate debt	1,001		(1		)	—		—		1,001		(1		)
Total	$	15,664	$	(60	)	$	—	$	—	$	15,664	$	(60	)

Amortized Cost and Fair Value of Fixed Maturity Securities by Contractual Maturity

The amortized cost and estimated fair value of the fixed maturity securities at December 31, 2017 by contractual maturity are set forth below:



(in thousands)	Amortized Cost		Fair Value
Years to maturity:
Due in one year or less	$	16,934	$	16,899
Due after one year through five years	13,876		13,708
Due after five years through ten years	232		241
Total	$	31,042	$	30,848

The amortized cost and estimated fair value of the fixed maturity securities at December 31, 2016 by contractual maturity are set forth below:



(in thousands)	Amortized Cost		Fair Value
Years to maturity:
Due in one year or less	$	5,551	$	5,554
Due after one year through five years	22,757		22,708
Due after five years through ten years	330		340
Total	$	28,638	$	28,602

Fixed Assets (Tables)

12 Months Ended

Dec. 31, 2017

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment [Table Text Block]

Fixed assets at December 31 consisted of the following:



(in thousands)	2017			2016
Furniture, fixtures and equipment	$	190,784		$	177,823
Leasehold improvements	35,481			33,137
Land, buildings and improvements	7,643			3,375
Total cost	233,908			214,335
Less accumulated depreciation and amortization	(156,822		)	(138,528		)
Total	$	77,086		$	75,807

Depreciation and amortization expense for fixed assets amounted to $22.7 million in 2017, $21.0 million in 2016 and $20.9 million in 2015.

Accrued Expenses (Tables) - USD ($)
$ in Thousands

12 Months Ended

Dec. 31, 2017

Dec. 31, 2016

Payables and Accruals [Abstract]

Other Current Liabilities [Table Text Block]

$ 10,951

$ 11,726

Accrued expenses and other liabilities

228,748

201,989

Interest Payable, Current

6,749

6,441

Reserve for policy cancellations

11,048

9,567

Accrued Rent and Vendor Expenses

30,616

28,669

Accrued Employee Benefits, Current

40,540

45,771

Accrued Bonuses

$ 106,923

82,438

Accounts Payable, Accrued Liabilities, and Other Liabilities Disclosure, Current [Text Block]

Accrued Expenses and Other Liabilities

Accrued expenses and other liabilities at December 31 consisted of the following:



(in thousands)	2017		2016
Accrued incentive compensation	$	106,923	$	82,438
Accrued compensation and benefits	40,540		45,771
Accrued rent and vendor expenses	30,616		28,669
Deferred revenue	21,921		17,377
Reserve for policy cancellations	11,048		9,567
Accrued interest	6,749		6,441
Other	10,951		11,726
Total	$	228,748	$	201,989

Schedule of Accrued Liabilities [Table Text Block]

Accrued expenses and other liabilities at December 31 consisted of the following:



(in thousands)	2017		2016
Accrued incentive compensation	$	106,923	$	82,438
Accrued compensation and benefits	40,540		45,771
Accrued rent and vendor expenses	30,616		28,669
Deferred revenue	21,921		17,377
Reserve for policy cancellations	11,048		9,567
Accrued interest	6,749		6,441
Other	10,951		11,726
Total	$	228,748	$	201,989

Deferred Revenue

$ 21,921

$ 17,377

Long-Term Debt (Tables)

12 Months Ended

Dec. 31, 2017

Debt Disclosure [Abstract]

Long-Term Debt Instrument

Long-term debt at December 31, 2017 and 2016 consisted of the following:



(in thousands)	December 31, 2017			December 31, 2016
Current portion of long-term debt:
Current portion of 5-year term loan facility expires 2019	$	20,000		$	55,000
4.500% senior notes, Series E, quarterly interest payments, balloon due 2018	100,000			—
Short-term promissory note	—			500
Total current portion of long-term debt	120,000			55,500
Long-term debt:
Note agreements:
4.500% senior notes, Series E, quarterly interest payments, balloon due 2018	—			100,000
4.200% senior notes, semi-annual interest payments, balloon due 2024	498,943			498,785
Total notes	498,943			598,785
Credit agreements:
5-year term loan facility, periodic interest and principal payments, LIBOR plus up to 1.750%, expires June 28, 2022	365,000			426,250
5-year revolving loan facility, periodic interest payments, currently LIBOR plus up to 1.500%, plus commitment fees up to 0.250%, expires June 28, 2022	—			—
Total credit agreements	365,000			426,250
Debt issuance costs (contra)	(7,802		)	(6,663		)
Total long-term debt less unamortized discount and debt issuance costs	856,141			1,018,372
Current portion of long-term debt	120,000			55,500
Total debt	$	976,141		$	1,073,872

- Definition

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21475-112644

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64711-112823

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(e),(f))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21538-112644

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21506-112644

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28541-108399

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21521-112644

+ Details

Income Taxes (Tables) - USD ($)
$ in Thousands

12 Months Ended

Dec. 31, 2017

Dec. 31, 2016

Dec. 31, 2015

Income Tax Contingency [Line Items]

Schedule of Deferred Tax Assets and Liabilities [Table Text Block]

ignificant components of Brown & Brown’s net deferred tax liabilities as of December 31 are as follows:



(in thousands)	2017			2016
Non-current deferred tax liabilities:
Intangible assets	$	306,351		$	422,478
Fixed assets	2,723			6,425
Net unrealized holding (loss)/gain on available-for-sale securities	(6		)	(12		)
Total non-current deferred tax liabilities	309,068			428,891
Non-current deferred tax assets:
Deferred compensation	36,701			44,912
Accruals and reserves	7,534			14,032
Deferred profit-sharing contingent commissions	7,107			10,567
Net operating loss carryforwards	2,434			2,394
Valuation allowance for deferred tax assets	(893		)	(700		)
Total non-current deferred tax assets	52,883			71,205
Net non-current deferred tax liability	$	256,185		$	357,686

Income Tax Disclosure [Text Block]

Income Taxes

Significant components of the provision for income taxes for the years ended December 31 are as follows:



(in thousands)	2017			2016		2015
Current:
Federal	$	129,954		$	126,145	$	118,490
State	21,392			21,110		17,625
Foreign	929			590		430
Total current provision	152,275			147,845		136,545
Deferred:
Federal	18,999			15,551		18,416
State	2,984			2,612		4,280
Foreign	—			—		—
Tax Reform Act deferred tax revaluation	(124,166		)	—		—
Total deferred provision	(102,183		)	18,163		22,696
Total tax provision	$	50,092		$	166,008	$	159,241

A reconciliation of the differences between the effective tax rate and the federal statutory tax rate for the years ended December 31 is as follows:



	2017	2016	2015
Federal statutory tax rate	35.0%	35.0%	35.0%
State income taxes, net of federal income tax benefit	3.8	3.9	3.9
Non-deductible employee stock purchase plan expense	0.3	0.3	0.3
Non-deductible meals and entertainment	0.3	0.3	0.3
Tax Reform Act deferred tax revaluation and transition tax impact	(26.9)	—	—
Other, net	(1.4)	(0.3)	0.1
Effective tax rate	11.1%	39.2%	39.6%

Significant components of Brown & Brown’s net deferred tax liabilities as of December 31 are as follows:



(in thousands)	2017			2016
Non-current deferred tax liabilities:
Intangible assets	$	306,351		$	422,478
Fixed assets	2,723			6,425
Net unrealized holding (loss)/gain on available-for-sale securities	(6		)	(12		)
Total non-current deferred tax liabilities	309,068			428,891
Non-current deferred tax assets:
Deferred compensation	36,701			44,912
Accruals and reserves	7,534			14,032
Deferred profit-sharing contingent commissions	7,107			10,567
Net operating loss carryforwards	2,434			2,394
Valuation allowance for deferred tax assets	(893		)	(700		)
Total non-current deferred tax assets	52,883			71,205
Net non-current deferred tax liability	$	256,185		$	357,686

Income taxes paid in 2017, 2016 and 2015 were $152.0 million, $143.1 million and $132.9 million, respectively.

A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows:



(in thousands)	2017			2016			2015
Unrecognized tax benefits balance at January 1	$	750		$	584		$	113
Gross increases for tax positions of prior years	1,070			412			773
Gross decreases for tax positions of prior years	—			(41		)	—
Settlements	(126		)	(205		)	(302		)
Unrecognized tax benefits balance at December 31	$	1,694		$	750		$	584

Summary of Income Tax Contingencies [Table Text Block]

$ (102,183)

$ 18,163

$ 22,696

Summary of Positions for which Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Table Text Block]

A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows:



(in thousands)	2017			2016			2015
Unrecognized tax benefits balance at January 1	$	750		$	584		$	113
Gross increases for tax positions of prior years	1,070			412			773
Gross decreases for tax positions of prior years	—			(41		)	—
Settlements	(126		)	(205		)	(302		)
Unrecognized tax benefits balance at December 31	$	1,694		$	750		$	584

Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]

Significant components of the provision for income taxes for the years ended December 31 are as follows:



(in thousands)	2017			2016		2015
Current:
Federal	$	129,954		$	126,145	$	118,490
State	21,392			21,110		17,625
Foreign	929			590		430
Total current provision	152,275			147,845		136,545
Deferred:
Federal	18,999			15,551		18,416
State	2,984			2,612		4,280
Foreign	—			—		—
Tax Reform Act deferred tax revaluation	(124,166		)	—		—
Total deferred provision	(102,183		)	18,163		22,696
Total tax provision	$	50,092		$	166,008	$	159,241

Stock Based Compensation (Tables) - USD ($)
$ in Thousands

12 Months Ended

Dec. 31, 2017

Dec. 31, 2016

Dec. 31, 2015

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Share-based Compensation

$ 30,631

$ 16,052

$ 15,513

Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block]

A summary of stock option activity for the years ended December 31, 2017, 2016 and 2015 is as follows:



Stock Options	Shares Under Option		Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value (in thousands)
Outstanding at January 1, 2015	470,356		$	18.57	3.1	$	5,087
Granted	—		$	—
Exercised	(151,767	)	$	18.48
Forfeited	(49,000	)	$	19.36
Expired	—		$	—
Outstanding at December 31, 2015	269,589		$	18.48	2.2	$	2,395
Granted	—		$	—
Exercised	(64,589	)	$	18.48
Forfeited	(30,000	)	$	18.48
Expired	—		$	—
Outstanding at December 31, 2016	175,000		$	18.48	1.2	$	4,616
Granted	—		$	—
Exercised	(175,000	)	$	18.48
Forfeited	—		$	—
Expired	—		$	—
Outstanding at December 31, 2017	—		$	—	N/A	$	—
Ending vested and expected to vest at December 31, 2017	—		$	—	N/A	$	—
Exercisable at December 31, 2017	—		$	—	N/A	$	—
Exercisable at December 31, 2016	175,000		$	18.48	1.2	$	4,616
Exercisable at December 31, 2015	164,589		$	18.48	2.2	$	2,241

A summary of SIP activity for the years ended December 31, 2017, 2016 and 2015 is as follows:



	Weighted- Average Grant Date Fair Value		Granted Shares		Awarded Shares		Shares Not Yet Awarded
Outstanding at January 1, 2015	$	28.19	6,659,047		1,060,890		5,598,157
Granted	$	31.74	481,166		164,646		316,520
Awarded	$	—	—		—		—
Vested	$	—	—		—		—
Forfeited	$	26.32	(863,241	)	(95,542	)	(767,699	)
Outstanding at December 31, 2015	$	28.74	6,276,972		1,129,994		5,146,978
Granted	$	35.52	972,099		182,653		789,446		⁽¹⁾
Awarded	$	24.93	—		1,431,319		(1,431,319	)
Vested	$	27.31	(166,884	)	(166,884	)	—
Forfeited	$	25.34	(954,131	)	(175,788	)	(778,343	)
Outstanding at December 31, 2016	$	29.96	6,128,056		2,401,294		3,726,762
Granted	$	41.65	696,456		120,667		575,789		⁽²⁾
Awarded	$	31.44	—		163,404		(163,404	)
Vested	$	25.22	(242,457	)	(242,457	)	—
Forfeited	$	29.77	(171,060	)	(38,106	)	(132,954	)
Outstanding at December 31, 2017	$	31.16	6,410,995		2,404,802		4,006,193

A summary of PSP activity for the years ended December 31, 2017, 2016 and 2015 is as follows:



	Weighted- Average Grant Date Fair Value		Granted Shares		Awarded Shares		Shares Not Yet Awarded
Outstanding at January 1, 2015	$	8.71	1,928,631		1,903,213		25,418
Granted	$	—	—		—		—
Awarded	$	—	—		—		—
Vested	$	5.55	(208,889	)	(208,889	)	—
Forfeited	$	9.78	(117,528	)	(100,110	)	(17,418	)
Outstanding at December 31, 2015	$	9.03	1,602,214		1,594,214		8,000
Granted	$	—	—		—		—
Awarded	$	—	—		4,000		(4,000	)
Vested	$	6.39	(506,422	)	(506,422	)	—
Forfeited	$	10.52	(92,517	)	(88,517	)	(4,000	)
Outstanding at December 31, 2016	$	10.23	1,003,275		1,003,275		—
Granted	$	—	—		—		—
Awarded	$	—	—		—		—
Vested	$	9.61	(138,801	)	(138,801	)	—
Forfeited	$	10.47	(17,236	)	(17,236	)	—
Outstanding at December 31, 2017	$	10.32	847,238		847,238		—

Stock Incentive Plan [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Share-based Compensation

$ 24,899

11,049

11,111

PerformanceStockPlan [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Share-based Compensation

1,707

1,305

972

Employee Stock [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Share-based Compensation

$ 4,025

$ 3,698

$ 3,430

Stock Based Compensation Summary of Stock Based Compensation Plan Activity (Tables)

12 Months Ended

Dec. 31, 2017

Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]

Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block]

A summary of stock option activity for the years ended December 31, 2017, 2016 and 2015 is as follows:



Stock Options	Shares Under Option		Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value (in thousands)
Outstanding at January 1, 2015	470,356		$	18.57	3.1	$	5,087
Granted	—		$	—
Exercised	(151,767	)	$	18.48
Forfeited	(49,000	)	$	19.36
Expired	—		$	—
Outstanding at December 31, 2015	269,589		$	18.48	2.2	$	2,395
Granted	—		$	—
Exercised	(64,589	)	$	18.48
Forfeited	(30,000	)	$	18.48
Expired	—		$	—
Outstanding at December 31, 2016	175,000		$	18.48	1.2	$	4,616
Granted	—		$	—
Exercised	(175,000	)	$	18.48
Forfeited	—		$	—
Expired	—		$	—
Outstanding at December 31, 2017	—		$	—	N/A	$	—
Ending vested and expected to vest at December 31, 2017	—		$	—	N/A	$	—
Exercisable at December 31, 2017	—		$	—	N/A	$	—
Exercisable at December 31, 2016	175,000		$	18.48	1.2	$	4,616
Exercisable at December 31, 2015	164,589		$	18.48	2.2	$	2,241

A summary of SIP activity for the years ended December 31, 2017, 2016 and 2015 is as follows:



	Weighted- Average Grant Date Fair Value		Granted Shares		Awarded Shares		Shares Not Yet Awarded
Outstanding at January 1, 2015	$	28.19	6,659,047		1,060,890		5,598,157
Granted	$	31.74	481,166		164,646		316,520
Awarded	$	—	—		—		—
Vested	$	—	—		—		—
Forfeited	$	26.32	(863,241	)	(95,542	)	(767,699	)
Outstanding at December 31, 2015	$	28.74	6,276,972		1,129,994		5,146,978
Granted	$	35.52	972,099		182,653		789,446		⁽¹⁾
Awarded	$	24.93	—		1,431,319		(1,431,319	)
Vested	$	27.31	(166,884	)	(166,884	)	—
Forfeited	$	25.34	(954,131	)	(175,788	)	(778,343	)
Outstanding at December 31, 2016	$	29.96	6,128,056		2,401,294		3,726,762
Granted	$	41.65	696,456		120,667		575,789		⁽²⁾
Awarded	$	31.44	—		163,404		(163,404	)
Vested	$	25.22	(242,457	)	(242,457	)	—
Forfeited	$	29.77	(171,060	)	(38,106	)	(132,954	)
Outstanding at December 31, 2017	$	31.16	6,410,995		2,404,802		4,006,193

A summary of PSP activity for the years ended December 31, 2017, 2016 and 2015 is as follows:



	Weighted- Average Grant Date Fair Value		Granted Shares		Awarded Shares		Shares Not Yet Awarded
Outstanding at January 1, 2015	$	8.71	1,928,631		1,903,213		25,418
Granted	$	—	—		—		—
Awarded	$	—	—		—		—
Vested	$	5.55	(208,889	)	(208,889	)	—
Forfeited	$	9.78	(117,528	)	(100,110	)	(17,418	)
Outstanding at December 31, 2015	$	9.03	1,602,214		1,594,214		8,000
Granted	$	—	—		—		—
Awarded	$	—	—		4,000		(4,000	)
Vested	$	6.39	(506,422	)	(506,422	)	—
Forfeited	$	10.52	(92,517	)	(88,517	)	(4,000	)
Outstanding at December 31, 2016	$	10.23	1,003,275		1,003,275		—
Granted	$	—	—		—		—
Awarded	$	—	—		—		—
Vested	$	9.61	(138,801	)	(138,801	)	—
Forfeited	$	10.47	(17,236	)	(17,236	)	—
Outstanding at December 31, 2017	$	10.32	847,238		847,238		—

Stock Based Compensation Stock Options Outstanding (Tables)

12 Months Ended

Dec. 31, 2017

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block]

A summary of stock option activity for the years ended December 31, 2017, 2016 and 2015 is as follows:



Stock Options	Shares Under Option		Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value (in thousands)
Outstanding at January 1, 2015	470,356		$	18.57	3.1	$	5,087
Granted	—		$	—
Exercised	(151,767	)	$	18.48
Forfeited	(49,000	)	$	19.36
Expired	—		$	—
Outstanding at December 31, 2015	269,589		$	18.48	2.2	$	2,395
Granted	—		$	—
Exercised	(64,589	)	$	18.48
Forfeited	(30,000	)	$	18.48
Expired	—		$	—
Outstanding at December 31, 2016	175,000		$	18.48	1.2	$	4,616
Granted	—		$	—
Exercised	(175,000	)	$	18.48
Forfeited	—		$	—
Expired	—		$	—
Outstanding at December 31, 2017	—		$	—	N/A	$	—
Ending vested and expected to vest at December 31, 2017	—		$	—	N/A	$	—
Exercisable at December 31, 2017	—		$	—	N/A	$	—
Exercisable at December 31, 2016	175,000		$	18.48	1.2	$	4,616
Exercisable at December 31, 2015	164,589		$	18.48	2.2	$	2,241

A summary of SIP activity for the years ended December 31, 2017, 2016 and 2015 is as follows:



	Weighted- Average Grant Date Fair Value		Granted Shares		Awarded Shares		Shares Not Yet Awarded
Outstanding at January 1, 2015	$	28.19	6,659,047		1,060,890		5,598,157
Granted	$	31.74	481,166		164,646		316,520
Awarded	$	—	—		—		—
Vested	$	—	—		—		—
Forfeited	$	26.32	(863,241	)	(95,542	)	(767,699	)
Outstanding at December 31, 2015	$	28.74	6,276,972		1,129,994		5,146,978
Granted	$	35.52	972,099		182,653		789,446		⁽¹⁾
Awarded	$	24.93	—		1,431,319		(1,431,319	)
Vested	$	27.31	(166,884	)	(166,884	)	—
Forfeited	$	25.34	(954,131	)	(175,788	)	(778,343	)
Outstanding at December 31, 2016	$	29.96	6,128,056		2,401,294		3,726,762
Granted	$	41.65	696,456		120,667		575,789		⁽²⁾
Awarded	$	31.44	—		163,404		(163,404	)
Vested	$	25.22	(242,457	)	(242,457	)	—
Forfeited	$	29.77	(171,060	)	(38,106	)	(132,954	)
Outstanding at December 31, 2017	$	31.16	6,410,995		2,404,802		4,006,193

A summary of PSP activity for the years ended December 31, 2017, 2016 and 2015 is as follows:



	Weighted- Average Grant Date Fair Value		Granted Shares		Awarded Shares		Shares Not Yet Awarded
Outstanding at January 1, 2015	$	8.71	1,928,631		1,903,213		25,418
Granted	$	—	—		—		—
Awarded	$	—	—		—		—
Vested	$	5.55	(208,889	)	(208,889	)	—
Forfeited	$	9.78	(117,528	)	(100,110	)	(17,418	)
Outstanding at December 31, 2015	$	9.03	1,602,214		1,594,214		8,000
Granted	$	—	—		—		—
Awarded	$	—	—		4,000		(4,000	)
Vested	$	6.39	(506,422	)	(506,422	)	—
Forfeited	$	10.52	(92,517	)	(88,517	)	(4,000	)
Outstanding at December 31, 2016	$	10.23	1,003,275		1,003,275		—
Granted	$	—	—		—		—
Awarded	$	—	—		—		—
Vested	$	9.61	(138,801	)	(138,801	)	—
Forfeited	$	10.47	(17,236	)	(17,236	)	—
Outstanding at December 31, 2017	$	10.32	847,238		847,238		—

Supplemental Disclosures of Cash Flow Information and Non-Cash Financing and Investing Activities (Tables)

12 Months Ended

Dec. 31, 2017

Supplemental Cash Flow Elements [Abstract]

Summary of Supplemental Disclosures of Cash Flow Information and Non-Cash Financing and Investing Activities

NOTE 12· Supplemental Disclosures of Cash Flow Information and Non-Cash Financing and Investing Activities

Our Restricted Cash balance is comprised of funds held in separate premium trust accounts as required by state law or, in some cases, per agreement with our carrier partners. While these referenced funds are not restricted, they do represent premium payments from customers to be paid to insurance carriers and this change in classification should not be viewed as a source of operating cash.



	For the Year Ended December 31,
(in thousands)	2017		2016		2015
Cash paid during the period for:
Interest	$	36,172	$	37,652	$	37,542
Income taxes	$	152,024	$	143,111	$	132,874

Brown & Brown’s significant non-cash investing and financing activities are summarized as follows:



	For the Year Ended December 31,
(in thousands)	2017		2016		2015
Other payables issued for purchased customer accounts	$	11,708	$	10,664	$	10,029
Estimated acquisition earn-out payables and related charges	$	6,921	$	4,463	$	36,899
Notes payable issued or assumed for purchased customer accounts	$	—	$	492	$	—
Notes received on the sale of fixed assets and customer accounts	$	—	$	22	$	7,755

The following is a reconciliation of cash and cash equivalents inclusive of restricted cash as of December 31, 2017, 2016 and 2015.



	Balance as of December 31,
(in thousands)	2017		2016		2015
Table to reconcile cash and cash equivalents inclusive of restricted cash
Cash and cash equivalents	$	573,383	$	515,646	443,420
Restricted cash	250,705		265,637		229,753
Total cash and cash equivalents inclusive of restricted cash at the end of the period	$	824,088	$	781,283	673,173

Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2017

Commitments and Contingencies Disclosure [Abstract]

Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]



(in thousands)
2018	$	42,970
2019	39,005
2020	34,236
2021	27,715
2022	21,996
Thereafter	44,496
Total minimum future lease payments	$	210,418

Rental expense in 2017, 2016 and 2015 for operating leases totaled $51.0 million, $49.3 million and $46.0 million, respectively.

Quarterly Operating Results (Tables)

12 Months Ended

Dec. 31, 2017

Quarterly Financial Information Disclosure [Abstract]

Schedule of Quarterly Financial Information [Table Text Block]

Quarterly operating results for 2017 and 2016 were as follows:



(in thousands, except per share data)	First Quarter		Second Quarter		Third Quarter		Fourth Quarter
2017
Total revenues	$	465,080	$	466,305	$	475,646	$	474,316
Total expenses	$	354,113	$	358,303	$	351,227	$	367,982
Income before income taxes	$	110,967	$	108,002	$	124,419	$	106,334
Net income	$	70,110	$	66,102	$	75,913	$	187,505
Net income per share:
Basic	$	0.50	$	0.47	$	0.54	$	1.35
Diluted	$	0.49	$	0.46	$	0.53	$	1.32	⁽¹⁾
2016
Total revenues	$	424,173	$	446,518	$	462,274	$	433,664
Total expenses	$	321,624	$	337,441	$	345,302	$	338,763
Income before income taxes	$	102,549	$	109,077	$	116,972	$	94,901
Net income	$	62,070	$	66,250	$	71,545	$	57,626
Net income per share:
Basic	$	0.45	$	0.47	$	0.51	$	0.41
Diluted	$	0.44	$	0.47	$	0.50	$	0.41

Segment Information (Tables)

12 Months Ended

Dec. 31, 2017

Segment Reporting Information [Line Items]

Segment Information



	For the year ended December 31, 2017
(in thousands)	Retail		National Programs		Wholesale Brokerage		Services		Other			Total
Total revenues	$	943,460	$	479,813	$	271,737	$	165,372	$	20,965		$	1,881,347
Investment income	$	8	$	384	$	—	$	299	$	935		$	1,626
Amortization	$	42,164	$	27,277	$	11,456	$	4,548	$	1		$	85,446
Depreciation	$	5,210	$	6,325	$	1,885	$	1,600	$	7,678		$	22,698
Interest expense	$	31,133	$	35,561	$	6,263	$	3,522	$	(38,163	)	$	38,316
Income before income taxes	$	196,616	$	109,961	$	68,844	$	30,498	$	43,803		$	449,722
Total assets	$	4,255,515	$	3,267,486	$	1,260,239	$	399,240	$	(3,434,930	)	$	5,747,550
Capital expenditures	$	4,494	$	5,936	$	1,836	$	1,033	$	10,893		$	24,192



	For the year ended December 31, 2016
(in thousands)	Retail		National Programs		Wholesale Brokerage		Services		Other			Total
Total revenues	$	917,406	$	448,516	$	243,103	$	156,365	$	1,239		$	1,766,629
Investment income	$	37	$	628	$	4	$	283	$	504		$	1,456
Amortization	$	43,447	$	27,920	$	10,801	$	4,485	$	10		$	86,663
Depreciation	$	6,191	$	7,868	$	1,975	$	1,881	$	3,088		$	21,003
Interest expense	$	38,216	$	45,738	$	3,976	$	4,950	$	(53,399	)	$	39,481
Income before income taxes	$	188,001	$	91,762	$	62,623	$	24,338	$	56,775		$	423,499
Total assets⁽¹⁾	$	3,854,393	$	2,711,378	$	1,108,829	$	371,645	$	(2,783,511	)	$	5,262,734
Capital expenditures	$	5,951	$	6,977	$	1,301	$	656	$	2,880		$	17,765



	For the year ended December 31, 2015
(in thousands)	Retail		National Programs		Wholesale Brokerage		Services		Other			Total
Total revenues	$	870,346	$	428,734	$	216,996	$	145,365	$	(932	)	$	1,660,509
Investment income	$	87	$	210	$	150	$	42	$	515		$	1,004
Amortization	$	45,145	$	28,479	$	9,739	$	4,019	$	39		$	87,421
Depreciation	$	6,558	$	7,250	$	2,142	$	1,988	$	2,952		$	20,890
Interest expense	$	41,036	$	55,705	$	891	$	5,970	$	(64,354	)	$	39,248
Income before income taxes	$	181,938	$	67,673	$	64,708	$	19,713	$	68,527		$	402,559
Total assets⁽¹⁾	$	3,507,476	$	2,503,537	$	895,782	$	285,459	$	(2,212,410	)	$	4,979,844
Capital expenditures	$	6,797	$	6,001	$	3,084	$	1,088	$	1,405		$	18,375

New Accounting Pronouncements (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Jan. 01, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred Tax Assets Netted Against Deferred Tax Liabilities	$ 24.6
Scenario, Forecast [Member] \| Minimum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets		$ 70.0
Scenario, Forecast [Member] \| Maximum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets		$ 110.0

- Definition

Amount of cumulative effect of the change in accounting principle or new accounting pronouncement on retained earnings or other components of equity or net assets in the statement of financial position as of the beginning of the earliest period presented.

+ References + Details

Net Income Per Share - Reconciliation between Basic and Diluted Weighted Average Shares Outstanding (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings Per Share [Abstract]
Net income	$ 187,505	$ 75,913	$ 66,102	$ 70,110	$ 57,626	$ 71,545	$ 66,250	$ 62,070	$ 399,630	$ 257,491	$ 243,318
Net income attributable to unvested awarded performance stock									(9,746)	(6,705)	(5,695)
Net income attributable to common shares									$ 389,884	$ 250,786	$ 237,623
Weighted average number of common shares outstanding - basic (in shares)									139,697	139,779	141,113
Less unvested awarded performance stock included in weighted average number of common shares outstanding - basic (in shares)									(3,407)	(3,640)	(3,303)
Weighted average number of common shares outstanding for basic earnings per common share (in shares)									136,290	136,139	137,810
Dilutive effect of stock options (in shares)									2,503	1,665	2,302
Weighted average number of shares outstanding - diluted (in shares)									138,793	137,804	140,112
Basic (in dollars per share)	$ 0.0135	$ 0.0054	$ 0.0047	$ 0.0050	$ 0.0041	$ 0.0051	$ 0.0047	$ 0.0045	$ 2.86	$ 1.84	$ 1.72
Diluted (in dollars per share)	$ 0.0132	$ 0.0053	$ 0.0046	$ 0.0049	$ 0.0041	$ 0.0050	$ 0.0047	$ 0.0044	$ 2.81	$ 1.82	$ 1.70

Business Combinations - Additional Information (Detail)	12 Months Ended
Business Combinations - Additional Information (Detail)	Dec. 31, 2017 USD ($) acquisition	Dec. 31, 2016 USD ($) acquisition	Dec. 31, 2015 USD ($) acquisition customer_account	Dec. 31, 2014 USD ($)
Business Acquisition [Line Items]
Maximum Future Contingency payments Acquisitions	$ 88,400,000
Number of acquisitions \| acquisition	11	8
Aggregate purchase price of acquisitions	$ 1,500,000	$ 917,497	$ 503,442
Payments to Acquire Businesses, Gross	41,471,000	124,716,000	136,000,000.0
Goodwill assigned	42,172,000	93,376,000	136,381,000
Goodwill currently deductible for income tax purposes	35,300,000	88,900,000	91,100,000
Goodwill currently non-deductible for income tax purposes			8,400,000
Goodwill related to the recorded earn-out payables	6,900,000	4,500,000	36,900,000
Total revenues related to acquisitions	7,800,000	34,200,000	28,200,000
Income before income taxes related to acquisitions	2,400,000	4,300,000	1,500,000
Estimated acquisition earn-out payables	36,175,000	63,821,000	78,387,000	$ 75,283,000
Other Payable	11,708,000	10,664,000	10,028,000
Business Acquisitions Contingent Consideration At Fair Value	6,921,000	4,462,000	36,899,000
Net Assets Acquired	60,100,000	140,334,000	182,927,000
Maximum Potential Earn- Out Payable	27,451,000	16,285,000	73,074,000
Accounts payable
Business Acquisition [Line Items]
Estimated acquisition earn-out payables	$ 25,100,000	$ 31,800,000	$ 25,300,000
Purchased customer accounts
Business Acquisition [Line Items]
Weighted average life (years)	15 years	15 years	15 years
Non-compete agreements
Business Acquisition [Line Items]
Weighted average life (years)	5 years	5 years	5 years
National Programs
Business Acquisition [Line Items]
Goodwill assigned	$ 7,200,000	$ 57,900,000	$ 18,000,000.0
Wholesale Brokerage [Member]
Business Acquisition [Line Items]
Goodwill assigned	1,200,000	(1,200)	4,600,000
Services [Member]
Business Acquisition [Line Items]
Goodwill assigned	700,000	22,400,000
Other non-current liability
Business Acquisition [Line Items]
Estimated acquisition earn-out payables	$ 11,100,000	32,000,000.0	$ 53,100,000
Social Security Advocates for the Disabled LLC [Member]
Business Acquisition [Line Items]
Goodwill assigned		22,352,000
Net Assets Acquired		$ 33,989,000
Social Security Advocates for the Disabled LLC [Member] \| Services [Member]
Business Acquisition [Line Items]
Effective Date of Acquisition		Feb. 01, 2016
Payments to Acquire Businesses, Gross		$ 32,526,000
Other Payable		0
Business Acquisitions Contingent Consideration At Fair Value		971,000
Net Assets Acquired		33,989,000
Maximum Potential Earn- Out Payable		3,500,000
Morstan General Agency, Inc [Member]
Business Acquisition [Line Items]
Goodwill assigned		51,454,000
Net Assets Acquired		$ 79,341,000
Morstan General Agency, Inc [Member] \| Wholesale Brokerage [Member]
Business Acquisition [Line Items]
Effective Date of Acquisition		Jun. 01, 2016
Payments to Acquire Businesses, Gross		$ 66,050,000
Other Payable		10,200,000
Business Acquisitions Contingent Consideration At Fair Value		3,091,000
Net Assets Acquired		79,341,000
Maximum Potential Earn- Out Payable		$ 5,000,000
Asset Acquisitions [Member]
Business Acquisition [Line Items]
Number of acquisitions \| acquisition	11	7	13
Book of Business Purchases [Member]
Business Acquisition [Line Items]
Number of acquisitions	1	3	4
Other Acquisitions [Member]
Business Acquisition [Line Items]
Goodwill assigned			$ 21,040,000
Net Assets Acquired			17,605,000
Other Acquisitions [Member] \| Various
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross	$ 41,471,000	$ 26,140,000	12,926,000
Other Payable	11,708,000	464,000	95,000
Business Acquisitions Contingent Consideration At Fair Value	6,921,000	400,000	4,584,000
Net Assets Acquired	60,100,000	27,004,000	17,605,000
Maximum Potential Earn- Out Payable	$ 27,451,000	$ 7,785,000	$ 8,212,000

Business Combinations - Acquisitions Accounted for Business Combinations (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Business Combination, Separately Recognized Transactions [Line Items]
Cash Paid	$ 41,471	$ 124,716	$ 136,000
Other Payable	11,708	10,664	10,028
Recorded Earn-Out Payable	6,921	4,462	36,899
Net Assets Acquired	60,100	140,334	182,927
Maximum Potential Earn- Out Payable	27,451	16,285	73,074
Liberty Insurance Brokers, Inc. and Affiliates [Member]
Business Combination, Separately Recognized Transactions [Line Items]
Net Assets Acquired			$ 14,981
Liberty Insurance Brokers, Inc. and Affiliates [Member] \| Retail
Business Combination, Separately Recognized Transactions [Line Items]
Effective Date of Acquisition			Feb. 01, 2015
Cash Paid			$ 12,000
Other Payable			0
Recorded Earn-Out Payable			2,981
Net Assets Acquired			14,981
Maximum Potential Earn- Out Payable			3,750
Spain Agency, Inc. (Spain)
Business Combination, Separately Recognized Transactions [Line Items]
Net Assets Acquired			$ 23,323
Spain Agency, Inc. (Spain) \| Retail
Business Combination, Separately Recognized Transactions [Line Items]
Effective Date of Acquisition			Mar. 01, 2015
Cash Paid			$ 20,706
Other Payable			0
Recorded Earn-Out Payable			2,617
Net Assets Acquired			23,323
Maximum Potential Earn- Out Payable			9,162
Bellingham Underwriters, Inc. [Member]
Business Combination, Separately Recognized Transactions [Line Items]
Net Assets Acquired			$ 12,829
Bellingham Underwriters, Inc. [Member] \| National Programs
Business Combination, Separately Recognized Transactions [Line Items]
Effective Date of Acquisition			May 01, 2015
Bellingham Underwriters, Inc. [Member] \| National Programs Divisions [Member]
Business Combination, Separately Recognized Transactions [Line Items]
Cash Paid			$ 9,007
Other Payable			500
Recorded Earn-Out Payable			3,322
Net Assets Acquired			12,829
Maximum Potential Earn- Out Payable			4,400
Fitness Insurance, LLC [Member]
Business Combination, Separately Recognized Transactions [Line Items]
Net Assets Acquired			$ 11,834
Fitness Insurance, LLC [Member] \| Retail
Business Combination, Separately Recognized Transactions [Line Items]
Effective Date of Acquisition			Jun. 01, 2015
Cash Paid			$ 9,455
Other Payable			0
Recorded Earn-Out Payable			2,379
Net Assets Acquired			11,834
Maximum Potential Earn- Out Payable			3,500
Other
Business Combination, Separately Recognized Transactions [Line Items]
Net Assets Acquired			$ 63,587
Other \| Retail
Business Combination, Separately Recognized Transactions [Line Items]
Effective Date of Acquisition			Jun. 01, 2015
Cash Paid			$ 49,600
Other Payable			400
Recorded Earn-Out Payable			13,587
Net Assets Acquired			63,587
Maximum Potential Earn- Out Payable			26,000
Bentrust Financial, Inc. [Member]
Business Combination, Separately Recognized Transactions [Line Items]
Net Assets Acquired			$ 10,852
Bentrust Financial, Inc. [Member] \| Retail
Business Combination, Separately Recognized Transactions [Line Items]
Effective Date of Acquisition			Dec. 01, 2015
Cash Paid			$ 10,142
Other Payable			391
Recorded Earn-Out Payable			319
Net Assets Acquired			10,852
Maximum Potential Earn- Out Payable			2,200
MBA Insurance Agency of Arizona, Inc. [Member]
Business Combination, Separately Recognized Transactions [Line Items]
Net Assets Acquired			$ 14,573
MBA Insurance Agency of Arizona, Inc. [Member] \| Retail
Business Combination, Separately Recognized Transactions [Line Items]
Effective Date of Acquisition			Dec. 01, 2015
Cash Paid			$ 68
Other Payable			8,442
Recorded Earn-Out Payable			6,063
Net Assets Acquired			14,573
Maximum Potential Earn- Out Payable			9,500
Smith Insurance, Inc. [Member]
Business Combination, Separately Recognized Transactions [Line Items]
Net Assets Acquired			$ 13,343
Smith Insurance, Inc. [Member] \| Retail
Business Combination, Separately Recognized Transactions [Line Items]
Effective Date of Acquisition			Dec. 01, 2015
Cash Paid			$ 12,096
Other Payable			200
Recorded Earn-Out Payable			1,047
Net Assets Acquired			13,343
Maximum Potential Earn- Out Payable			6,350
Other Acquisitions [Member]
Business Combination, Separately Recognized Transactions [Line Items]
Net Assets Acquired			17,605
Other Acquisitions [Member] \| Various
Business Combination, Separately Recognized Transactions [Line Items]
Cash Paid	41,471	26,140	12,926
Other Payable	11,708	464	95
Recorded Earn-Out Payable	6,921	400	4,584
Net Assets Acquired	60,100	27,004	17,605
Maximum Potential Earn- Out Payable	$ 27,451	7,785	$ 8,212
Various
Business Combination, Separately Recognized Transactions [Line Items]
Net Assets Acquired		$ 27,004
Two Thousand Fifteen Acquisitions [Member]
Business Combination, Separately Recognized Transactions [Line Items]
Business Acquisition, Pro Forma Income (Loss) from Continuing Operations before Changes in Accounting and Extraordinary Items, Net of Tax, Per Share, Diluted			$ 1.73
Pro Forma Weighted Average Shares Outstanding, Diluted			140,112

Business Combinations - Estimated Fair Values of Aggregate Assets and Liabilities Acquired (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Fair Value Of Assets And Liabilities Statement [Line Items]
Other Payable	$ 11,708,000	$ 10,664,000	$ 10,028,000
Payments to Acquire Businesses, Gross	41,471,000	124,716,000	136,000,000.0
Recorded Earn-Out Payable	6,921,000	4,462,000	36,899,000
Business Acquisition Purchase Price Allocation Current Assets Prepaid Expenses And Other Assets		2,094,000
Business Acquisition Purchase Price Allocation Current Assets Prepaid Expenses And Other Assets	601,000	5,079,000	3,640,000
Fixed assets	69,000	684,000	374,000
Goodwill	42,172,000	93,376,000	136,381,000
Purchased customer accounts	18,738,000	50,625,000	53,392,000
Non-compete agreements	721,000	228,000	328,000
Business Acquisitions Purchase Price Allocation Other Noncurrent Assets		20,000	14,000
Total assets acquired	62,301,000	152,106,000	194,129,000
Other current liabilities	(1,512,000)	(8,542,000)	(12,213,000)
Deferred Tax Liabilities, Net	(689,000)	(3,230,000)
Deferred Tax Assets, Net			2,576,000
Other liabilities			(1,565,000)
Total liabilities assumed	(2,201,000)	(11,772,000)	(11,202,000)
Net assets acquired	60,100,000	140,334,000	182,927,000
Maximum Potential Earn- Out Payable	27,451,000	16,285,000	73,074,000
Social Security Advocates for the Disabled LLC [Member]
Fair Value Of Assets And Liabilities Statement [Line Items]
Business Acquisition Purchase Price Allocation Current Assets Prepaid Expenses And Other Assets		2,094,000
Business Acquisition Purchase Price Allocation Current Assets Prepaid Expenses And Other Assets		1,042,000
Fixed assets		307,000
Goodwill		22,352,000
Purchased customer accounts		13,069,000
Non-compete agreements		72,000
Business Acquisitions Purchase Price Allocation Other Noncurrent Assets		0
Total assets acquired		38,936,000
Other current liabilities		(1,717,000)
Deferred Tax Liabilities, Net		(3,230,000)
Total liabilities assumed		(4,947,000)
Net assets acquired		33,989,000
Various [Member]
Fair Value Of Assets And Liabilities Statement [Line Items]
Business Acquisition Purchase Price Allocation Current Assets Prepaid Expenses And Other Assets		0
Business Acquisition Purchase Price Allocation Current Assets Prepaid Expenses And Other Assets		1,555,000
Fixed assets		77,000
Goodwill		19,570,000
Purchased customer accounts		11,075,000
Non-compete agreements		117,000
Business Acquisitions Purchase Price Allocation Other Noncurrent Assets		20,000
Total assets acquired		32,414,000
Other current liabilities		(5,410,000)
Deferred Tax Liabilities, Net		0
Total liabilities assumed		(5,410,000)
Net assets acquired		27,004,000
Morstan General Agency, Inc [Member]
Fair Value Of Assets And Liabilities Statement [Line Items]
Business Acquisition Purchase Price Allocation Current Assets Prepaid Expenses And Other Assets		0
Business Acquisition Purchase Price Allocation Current Assets Prepaid Expenses And Other Assets		2,482,000
Fixed assets		300,000
Goodwill		51,454,000
Purchased customer accounts		26,481,000
Non-compete agreements		39,000
Business Acquisitions Purchase Price Allocation Other Noncurrent Assets		0
Total assets acquired		80,756,000
Other current liabilities		(1,415,000)
Deferred Tax Liabilities, Net		0
Total liabilities assumed		(1,415,000)
Net assets acquired		79,341,000
Spain Agency, Inc. (Spain)
Fair Value Of Assets And Liabilities Statement [Line Items]
Business Acquisition Purchase Price Allocation Current Assets Prepaid Expenses And Other Assets			324,000
Fixed assets			50,000
Goodwill			15,748,000
Purchased customer accounts			7,430,000
Non-compete agreements			21,000
Business Acquisitions Purchase Price Allocation Other Noncurrent Assets			0
Total assets acquired			23,573,000
Other current liabilities			(250,000)
Deferred Tax Liabilities, Net			0
Other liabilities			0
Total liabilities assumed			(250,000)
Net assets acquired			23,323,000
Bellingham Underwriters, Inc. [Member]
Fair Value Of Assets And Liabilities Statement [Line Items]
Business Acquisition Purchase Price Allocation Current Assets Prepaid Expenses And Other Assets			0
Fixed assets			25,000
Goodwill			9,608,000
Purchased customer accounts			3,223,000
Non-compete agreements			21,000
Business Acquisitions Purchase Price Allocation Other Noncurrent Assets			0
Total assets acquired			12,877,000
Other current liabilities			(48,000)
Deferred Tax Liabilities, Net			0
Other liabilities			0
Total liabilities assumed			(48,000)
Net assets acquired			12,829,000
Fitness Insurance, LLC [Member]
Fair Value Of Assets And Liabilities Statement [Line Items]
Business Acquisition Purchase Price Allocation Current Assets Prepaid Expenses And Other Assets			9,000
Fixed assets			17,000
Goodwill			8,105,000
Purchased customer accounts			3,715,000
Non-compete agreements			0
Business Acquisitions Purchase Price Allocation Other Noncurrent Assets			0
Total assets acquired			11,846,000
Other current liabilities			(12,000)
Deferred Tax Liabilities, Net			0
Other liabilities			0
Total liabilities assumed			(12,000)
Net assets acquired			11,834,000
Other
Fair Value Of Assets And Liabilities Statement [Line Items]
Business Acquisition Purchase Price Allocation Current Assets Prepaid Expenses And Other Assets			652,000
Fixed assets			41,000
Goodwill			39,859,000
Purchased customer accounts			23,000,000
Non-compete agreements			21,000
Business Acquisitions Purchase Price Allocation Other Noncurrent Assets			14,000
Total assets acquired			63,587,000
Other current liabilities			0
Deferred Tax Liabilities, Net			0
Other liabilities			0
Total liabilities assumed			0
Net assets acquired			63,587,000
Bentrust Financial, Inc. [Member]
Fair Value Of Assets And Liabilities Statement [Line Items]
Business Acquisition Purchase Price Allocation Current Assets Prepaid Expenses And Other Assets			0
Fixed assets			36,000
Goodwill			8,166,000
Purchased customer accounts			2,789,000
Non-compete agreements			43,000
Business Acquisitions Purchase Price Allocation Other Noncurrent Assets			0
Total assets acquired			11,034,000
Other current liabilities			(182,000)
Deferred Tax Liabilities, Net			0
Other liabilities			0
Total liabilities assumed			(182,000)
Net assets acquired			10,852,000
MBA Insurance Agency of Arizona, Inc. [Member]
Fair Value Of Assets And Liabilities Statement [Line Items]
Business Acquisition Purchase Price Allocation Current Assets Prepaid Expenses And Other Assets			0
Fixed assets			33,000
Goodwill			13,471,000
Purchased customer accounts			7,338,000
Non-compete agreements			11,000
Business Acquisitions Purchase Price Allocation Other Noncurrent Assets			0
Total assets acquired			20,853,000
Other current liabilities			(6,280,000)
Deferred Tax Liabilities, Net			0
Other liabilities			0
Total liabilities assumed			(6,280,000)
Net assets acquired			14,573,000
Smith Insurance, Inc. [Member]
Fair Value Of Assets And Liabilities Statement [Line Items]
Business Acquisition Purchase Price Allocation Current Assets Prepaid Expenses And Other Assets			0
Fixed assets			73,000
Goodwill			10,374,000
Purchased customer accounts			3,526,000
Non-compete agreements			31,000
Business Acquisitions Purchase Price Allocation Other Noncurrent Assets			0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Prepaid Expense and Other Assets			14,004,000
Other current liabilities			(504,000)
Deferred Tax Liabilities, Net			0
Other liabilities			(157,000)
Total liabilities assumed			(661,000)
Net assets acquired			13,343,000
Other Acquisitions [Member]
Fair Value Of Assets And Liabilities Statement [Line Items]
Business Acquisition Purchase Price Allocation Current Assets Prepaid Expenses And Other Assets			169,000
Fixed assets			59,000
Goodwill			21,040,000
Purchased customer accounts			(2,135,000)
Non-compete agreements			156,000
Business Acquisitions Purchase Price Allocation Other Noncurrent Assets			0
Total assets acquired			19,289,000
Other current liabilities			(4,895,000)
Deferred Tax Assets, Net			2,576,000
Other liabilities			635,000
Total liabilities assumed			(1,684,000)
Net assets acquired			17,605,000
Liberty Insurance Brokers, Inc. and Affiliates [Member]
Fair Value Of Assets And Liabilities Statement [Line Items]
Business Acquisition Purchase Price Allocation Current Assets Prepaid Expenses And Other Assets			2,486,000
Fixed assets			40,000
Goodwill			10,010,000
Purchased customer accounts			4,506,000
Non-compete agreements			24,000
Business Acquisitions Purchase Price Allocation Other Noncurrent Assets			0
Total assets acquired			17,066,000
Other current liabilities			(42,000)
Deferred Tax Liabilities, Net			0
Other liabilities			(2,043,000)
Total liabilities assumed			(2,085,000)
Net assets acquired			14,981,000
Services
Fair Value Of Assets And Liabilities Statement [Line Items]
Goodwill	700,000	$ 22,400,000
Services \| Social Security Advocates for the Disabled LLC [Member]
Fair Value Of Assets And Liabilities Statement [Line Items]
Effective Date of Acquisition		Feb. 01, 2016
Other Payable		$ 0
Payments to Acquire Businesses, Gross		32,526,000
Recorded Earn-Out Payable		971,000
Net assets acquired		33,989,000
Maximum Potential Earn- Out Payable		3,500,000
Retail
Fair Value Of Assets And Liabilities Statement [Line Items]
Goodwill	33,100,000	13,100,000	$ 113,800,000
Retail \| Spain Agency, Inc. (Spain)
Fair Value Of Assets And Liabilities Statement [Line Items]
Effective Date of Acquisition			Mar. 01, 2015
Other Payable			$ 0
Payments to Acquire Businesses, Gross			20,706,000
Recorded Earn-Out Payable			2,617,000
Net assets acquired			23,323,000
Maximum Potential Earn- Out Payable			$ 9,162,000
Retail \| Fitness Insurance, LLC [Member]
Fair Value Of Assets And Liabilities Statement [Line Items]
Effective Date of Acquisition			Jun. 01, 2015
Other Payable			$ 0
Payments to Acquire Businesses, Gross			9,455,000
Recorded Earn-Out Payable			2,379,000
Net assets acquired			11,834,000
Maximum Potential Earn- Out Payable			$ 3,500,000
Retail \| Other
Fair Value Of Assets And Liabilities Statement [Line Items]
Effective Date of Acquisition			Jun. 01, 2015
Other Payable			$ 400,000
Payments to Acquire Businesses, Gross			49,600,000
Recorded Earn-Out Payable			13,587,000
Net assets acquired			63,587,000
Maximum Potential Earn- Out Payable			$ 26,000,000
Retail \| Bentrust Financial, Inc. [Member]
Fair Value Of Assets And Liabilities Statement [Line Items]
Effective Date of Acquisition			Dec. 01, 2015
Other Payable			$ 391,000
Payments to Acquire Businesses, Gross			10,142,000
Recorded Earn-Out Payable			319,000
Net assets acquired			10,852,000
Maximum Potential Earn- Out Payable			$ 2,200,000
Retail \| MBA Insurance Agency of Arizona, Inc. [Member]
Fair Value Of Assets And Liabilities Statement [Line Items]
Effective Date of Acquisition			Dec. 01, 2015
Other Payable			$ 8,442,000
Payments to Acquire Businesses, Gross			68,000
Recorded Earn-Out Payable			6,063,000
Net assets acquired			14,573,000
Maximum Potential Earn- Out Payable			$ 9,500,000
Retail \| Smith Insurance, Inc. [Member]
Fair Value Of Assets And Liabilities Statement [Line Items]
Effective Date of Acquisition			Dec. 01, 2015
Other Payable			$ 200,000
Payments to Acquire Businesses, Gross			12,096,000
Recorded Earn-Out Payable			1,047,000
Net assets acquired			13,343,000
Maximum Potential Earn- Out Payable			$ 6,350,000
Retail \| Liberty Insurance Brokers, Inc. and Affiliates [Member]
Fair Value Of Assets And Liabilities Statement [Line Items]
Effective Date of Acquisition			Feb. 01, 2015
Other Payable			$ 0
Payments to Acquire Businesses, Gross			12,000,000
Recorded Earn-Out Payable			2,981,000
Net assets acquired			14,981,000
Maximum Potential Earn- Out Payable			3,750,000
National Programs
Fair Value Of Assets And Liabilities Statement [Line Items]
Goodwill	7,200,000	57,900,000	$ 18,000,000.0
National Programs \| Bellingham Underwriters, Inc. [Member]
Fair Value Of Assets And Liabilities Statement [Line Items]
Effective Date of Acquisition			May 01, 2015
Wholesale Brokerage
Fair Value Of Assets And Liabilities Statement [Line Items]
Goodwill	$ 1,200,000	$ (1,200)	$ 4,600,000
Wholesale Brokerage \| Morstan General Agency, Inc [Member]
Fair Value Of Assets And Liabilities Statement [Line Items]
Effective Date of Acquisition		Jun. 01, 2016
Other Payable		$ 10,200,000
Payments to Acquire Businesses, Gross		66,050,000
Recorded Earn-Out Payable		3,091,000
Net assets acquired		79,341,000
Maximum Potential Earn- Out Payable		$ 5,000,000

Business Combinations - Results of Operations (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual	$ 7,800	$ 34,200	$ 28,200
Business Combination Pro Forma Information Income Loss Before Income Taxes Of Acquiree Since Acquisition Date Actual	2,400	4,300	1,500
Two Thousand Seventeen Acquisition [Member] [Domain]
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Total revenues	1,891,701	1,784,776
Income before income taxes	453,397	429,490
Net income	$ 401,908	$ 261,133
Net income per share:
Basic (in dollars per share)	$ 2.88	$ 1.87
Business Acquisition, Pro Forma Income (Loss) from Continuing Operations before Changes in Accounting and Extraordinary Items, Net of Tax, Per Share, Diluted	$ 2.83	$ 1.85
Weighted Average Basic Shares Outstanding, Pro Forma	136,290	136,139
Weighted average number of shares outstanding:
Pro Forma Weighted Average Shares Outstanding, Diluted	138,793	137,804
Two Thousand Fifteen Acquisitions [Member]
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Total revenues			1,688,297
Income before income taxes			411,497
Net income			$ 248,720
Net income per share:
Basic (in dollars per share)			$ 1.76
Business Acquisition, Pro Forma Income (Loss) from Continuing Operations before Changes in Accounting and Extraordinary Items, Net of Tax, Per Share, Diluted			$ 1.73
Weighted Average Basic Shares Outstanding, Pro Forma			137,810
Weighted average number of shares outstanding:
Pro Forma Weighted Average Shares Outstanding, Diluted			140,112

Business Combinations - Additions, Payments, and Net Changes, as well as Interest Expense Accretion on Estimated Acquisition Earn-Out Payables (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Business Acquisition Cost- Note Payable		$ 492
Beginning balance	$ 63,821	78,387	$ 75,283
Additions to estimated acquisition earn-out payables	6,920	4,462	36,899
Payments for estimated acquisition earn-out payables	43,766	28,213	36,798
Subtotal	26,975	54,636	75,384
Net change in earnings from estimated acquisition earn-out payables:
Change in fair value on estimated acquisition earn-out payables	(6,874)	(6,338)	(13)
Interest expense accretion	2,326	2,847	2,990
Net change in earnings from estimated acquisition earn-out payables	9,200	9,185	3,003
Ending balance	$ 36,175	63,821	$ 78,387
Services \| Social Security Advocates for the Disabled LLC [Member]
Business Acquisition [Line Items]
Business Acquisition Cost- Note Payable		492
Wholesale Brokerage [Member] \| Morstan General Agency, Inc [Member]
Business Acquisition [Line Items]
Business Acquisition Cost- Note Payable		0
Various [Member] \| Other Acquisitions [Member]
Business Acquisition [Line Items]
Business Acquisition Cost- Note Payable		$ 0

Business Combinations Business Acquisitions - Pro-forma Table (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Two Thousand Sixteen Acquisition [Member]
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Weighted Average Basic Shares Outstanding, Pro Forma		136,139	137,810
Business Acquisition, Pro Forma Revenue		$ 1,789,790	$ 1,716,592
Business Acquisition, Pro Forma Income (Loss) from Continuing Operations before Changes in Accounting and Extraordinary Items, Net of Tax		428,194	414,911
Business Acquisition, Pro Forma Net Income (Loss)		$ 260,346	$ 250,783
Business Acquisition, Pro Forma Income (Loss) from Continuing Operations before Changes in Accounting and Extraordinary Items, Net of Tax, Per Share, Basic		$ 1.86	$ 1.78
Business Acquisition, Pro Forma Income (Loss) from Continuing Operations before Changes in Accounting and Extraordinary Items, Net of Tax, Per Share, Diluted		$ 1.84	$ 1.75
Pro Forma Weighted Average Shares Outstanding, Diluted		137,804	140,112
Two Thousand Fifteen Acquisitions [Member]
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Weighted Average Basic Shares Outstanding, Pro Forma			137,810
Business Acquisition, Pro Forma Revenue			$ 1,688,297
Business Acquisition, Pro Forma Income (Loss) from Continuing Operations before Changes in Accounting and Extraordinary Items, Net of Tax			411,497
Business Acquisition, Pro Forma Net Income (Loss)			$ 248,720
Business Acquisition, Pro Forma Income (Loss) from Continuing Operations before Changes in Accounting and Extraordinary Items, Net of Tax, Per Share, Basic			$ 1.76
Business Acquisition, Pro Forma Income (Loss) from Continuing Operations before Changes in Accounting and Extraordinary Items, Net of Tax, Per Share, Diluted			$ 1.73
Pro Forma Weighted Average Shares Outstanding, Diluted			140,112
Two Thousand Seventeen Acquisition [Member] [Domain]
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Weighted Average Basic Shares Outstanding, Pro Forma	136,290	136,139
Business Acquisition, Pro Forma Revenue	$ 1,891,701	$ 1,784,776
Business Acquisition, Pro Forma Income (Loss) from Continuing Operations before Changes in Accounting and Extraordinary Items, Net of Tax	453,397	429,490
Business Acquisition, Pro Forma Net Income (Loss)	$ 401,908	$ 261,133
Business Acquisition, Pro Forma Income (Loss) from Continuing Operations before Changes in Accounting and Extraordinary Items, Net of Tax, Per Share, Basic	$ 2.88	$ 1.87
Business Acquisition, Pro Forma Income (Loss) from Continuing Operations before Changes in Accounting and Extraordinary Items, Net of Tax, Per Share, Diluted	$ 2.83	$ 1.85
Pro Forma Weighted Average Shares Outstanding, Diluted	138,793	137,804

Goodwill - Changes in Carrying Value of Goodwill by Operating Segment (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Goodwill [Roll Forward]
Beginning balance	$ 2,675,402	$ 2,586,683
Goodwill of acquired businesses	42,172	93,376
Goodwill disposed of relating to sales of businesses	(1,495)	(4,657)
Ending balance	2,716,079	2,675,402
Retail
Goodwill [Roll Forward]
Beginning balance	1,354,667	1,345,636
Goodwill of acquired businesses	33,076	13,117
Goodwill disposed of relating to sales of businesses	(1,495)	(4,657)
Ending balance	1,386,248	1,354,667
National Programs
Goodwill [Roll Forward]
Beginning balance	901,294	901,866
Goodwill of acquired businesses	7,178	(1)
Goodwill disposed of relating to sales of businesses	0	0
Ending balance	908,472	901,294
Wholesale Brokerage
Goodwill [Roll Forward]
Beginning balance	284,869	226,961
Goodwill of acquired businesses	1,229	57,908
Goodwill disposed of relating to sales of businesses	0	0
Ending balance	286,098	284,869
Services
Goodwill [Roll Forward]
Beginning balance	134,572	112,220
Goodwill of acquired businesses	689	22,352
Goodwill disposed of relating to sales of businesses	0	0
Ending balance	$ 135,261	$ 134,572

Amortizable Intangible Assets - Amortizable Intangible Assets (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 1,494,561	$ 1,477,348
Accumulated Amortization	(853,556)	(769,894)
Net Carrying Value	641,005	707,454
Purchased customer accounts
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	1,464,274	1,447,680
Accumulated Amortization	(824,584)	(741,770)
Net Carrying Value	$ 639,690	$ 705,910
Weighted Average Life (Years)	15 years	15 years
Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 30,287	$ 29,668
Accumulated Amortization	(28,972)	(28,124)
Net Carrying Value	$ 1,315	$ 1,544
Weighted Average Life (Years)	6 years 9 months 18 days	6 years 9 months 18 days

Amortizable Intangible Assets - Additional Information (Detail) $ in Millions	Dec. 31, 2017 USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense estimated, year one (2015)	$ 81.0
Amortization expense estimated, year two (2016)	76.5
Amortization expense estimated, year three (2017)	69.1
Amortization expense estimated, year four (2018)	65.9
Amortization expense estimated, year five (2019)	$ 61.4

Investments - Schedule of Investments in Fixed Maturity Securities (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Proceeds from Sale, Maturity and Collection of Investments	$ 9,644	$ 18,890	$ 21,928
Cost	31,042	28,638
Gross Unrealized Gains	12	24
Gross Unrealized Losses	(206)	(60)
Fair Value	30,848	$ 28,602
Short-term Debt [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	$ 16,900

Investments - Summary of Unrealized Loss Position (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	$ 31,042	$ 28,638
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	12	24
Fair Value, Less than 12 Months	18,319	15,664
Unrealized Losses, Less than 12 Months	(157)	(60)
Fair Value, 12 Months or More	11,845	0
Unrealized Losses, 12 Months or More	(49)	0
Fair Value	30,164	15,664
Unrealized Losses	(206)	(60)
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	(206)	(60)
Available-for-sale Securities	30,848	28,602
U.S. Treasury securities, obligations of U.S. Government agencies and Municipals
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	29,970	26,280
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	0	11
Fair Value, Less than 12 Months	17,919	14,663
Unrealized Losses, Less than 12 Months	(157)	(59)
Fair Value, 12 Months or More	11,845	0
Unrealized Losses, 12 Months or More	(49)	0
Fair Value	29,764	14,663
Unrealized Losses	(206)	(59)
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	(206)	(59)
Available-for-sale Securities	29,764	26,232
Corporate debt
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	1,072	2,358
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	12	13
Fair Value, Less than 12 Months	400	1,001
Unrealized Losses, Less than 12 Months	0	(1)
Fair Value, 12 Months or More	0	0
Unrealized Losses, 12 Months or More	0	0
Fair Value	400	1,001
Unrealized Losses	0	(1)
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	0	(1)
Available-for-sale Securities	$ 1,084	$ 2,370

Investments - Additional Information (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($) Securities	Dec. 31, 2016 USD ($) Securities
Schedule of Available-for-sale Securities [Line Items]
Short-term Investments	$ 24,965	$ 15,048
Number of securities in unrealized loss position \| Securities	27	20
Proceeds from sale of investment in fixed maturity securities	$ 5,800	$ 6,000
Money Market Funds, at Carrying Value		$ 9,100
Investments on deposit with the state insurance department	4,100
Time Deposits	$ 8,100

Investments - Amortized Cost and Fair Value of Fixed Maturity Securities by Contractual Maturity (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Amortized Cost
Due in one year or less	$ 16,934	$ 5,551
Due after one year through five years	13,876	22,757
Due after five years through ten years	232	330
Amortized Cost, Total	31,042	28,638
Fair Value
Due in one year or less	16,899	5,554
Due after one year through five years	13,708	22,708
Due after five years through ten years	241	340
Fair Value, Total	$ 30,848	$ 28,602

Fixed Assets (Details) - USD ($) $ in Thousands	12 Months Ended
Fixed Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Depreciation	$ 22,698	$ 21,003	$ 20,890
Property, Plant and Equipment, Gross	233,908	214,335
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	(156,822)	(138,528)
Property, Plant and Equipment, Net	77,086	75,807
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	190,784	177,823
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	35,481	33,137
Land, Buildings and Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 7,643	$ 3,375

Long-Term Debt - Long-Term Debt Instrument (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 22, 2016
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Year Five	$ 255,000
Document Period End Date	Dec. 31, 2017
Total current portion of long-term debt	$ 120,000	$ 55,500
Total notes	498,943	598,785
Long-term credit agreements	365,000	426,250
Debt Issuance Costs, Net	(7,802)	(6,663)
Total long-term debt	856,141	1,018,372
Current portion of long-term debt	120,000	55,500
Total debt	976,141	1,073,872
Increase (Decrease) in Notes Payable, Current	0	500
5.370% senior notes, Series D, quarterly interest payments, balloon due 2015
Debt Instrument [Line Items]
Current portion of senior notes			$ 25,000
5.660% senior notes, Series C, semi-annual interest payments, balloon due 2016
Debt Instrument [Line Items]
Current portion of senior notes	100,000	0
4.500% senior notes, Series E, quarterly interest payments, balloon due 2018
Debt Instrument [Line Items]
Total notes	0	100,000
4.200% senior notes, semi-annual interest payments, balloon due 2024
Debt Instrument [Line Items]
Total notes	498,943	498,785
5-year term loan facility, periodic interest and principal payments, LIBOR plus up to 1.750%, expires June 28, 2022
Debt Instrument [Line Items]
Current portion of loan facility	20,000	55,000
Long-term credit agreements	365,000	426,250
5-year revolving loan facility, periodic interest payments, currently LIBOR plus up to 1.500%, plus commitment fees up to 0.250%, expires June 28, 2022
Debt Instrument [Line Items]
Long-term credit agreements	$ 0	$ 0

Long-Term Debt - Long-Term Debt Instrument (Additional Information) (Detail)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage		0.81%
5.660% senior notes, Series C, semi-annual interest payments, balloon due 2016
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	4.50%	4.50%
4.500% senior notes, Series E, quarterly interest payments, balloon due 2018
Debt Instrument [Line Items]
Debt instrument maturity year	2018	2018
4.200% senior notes, semi-annual interest payments, balloon due 2024
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	4.20%	4.20%
Debt instrument maturity year	2024	2024
5-year term loan facility, periodic interest and principal payments, LIBOR plus up to 1.750%, expires June 28, 2022
Debt Instrument [Line Items]
Line of credit facility, expiration period	5 years	5 years
Line of credit facility, expiration date	Jun. 28, 2022	May 20, 2019
5-year term loan facility, periodic interest and principal payments, LIBOR plus up to 1.750%, expires June 28, 2022 \| LIBOR
Debt Instrument [Line Items]
Debt instrument, variable interest rate	1.75%	1.75%
5-year revolving loan facility, periodic interest payments, currently LIBOR plus up to 1.500%, plus commitment fees up to 0.250%, expires June 28, 2022
Debt Instrument [Line Items]
Line of credit facility, expiration period	5 years	5 years
Line of credit facility, commitment fee percentage	0.25%	0.25%
Line of credit facility, expiration date	Jun. 28, 2022	May 20, 2019
5-year revolving loan facility, periodic interest payments, currently LIBOR plus up to 1.500%, plus commitment fees up to 0.250%, expires June 28, 2022 \| LIBOR
Debt Instrument [Line Items]
Debt instrument, variable interest rate	1.50%	1.50%

Long-Term Debt - Narrative (Detail)		3 Months Ended	12 Months Ended
Long-Term Debt - Narrative (Detail)	May 20, 2014 USD ($) extension	Sep. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Mar. 31, 2018 USD ($)	Jun. 28, 2017 USD ($)	Dec. 22, 2016 USD ($)	Jan. 15, 2015 USD ($)	Sep. 18, 2014 USD ($)	Apr. 17, 2014 USD ($)	Sep. 15, 2011 USD ($)	Feb. 01, 2008 USD ($)	Dec. 22, 2006 USD ($)
Debt Instrument [Line Items]
Proceeds from Issuance of Debt		$ 2,800,000
Write off of Deferred Debt Issuance Cost		200,000
Debt Issuance Costs, Noncurrent, Net						$ 1,600,000
Debt instrument interest rate stated percentage				0.81%
Credit facility, outstanding amount			$ 365,000,000	$ 426,250,000
Revolving and term loan			385,000,000.0
Potential increased in line of credit facility										$ 500,000,000.0
Unsecured revolving credit facility						$ 400,000,000.0				800,000,000.0
Debt Instrument, Periodic Payment, Principal		5,000,000.0
Unsecured term loans			385,000,000.0							550,000,000.0
Outstanding debt balance			976,141,000	1,073,872,000
Notes Payable, Current				500,000
Senior Notes Due Two Thousand Sixteen [Member]
Debt Instrument [Line Items]
Current portion of senior notes								$ 25,000,000.0
5.370% senior notes, Series D, quarterly interest payments, balloon due 2015
Debt Instrument [Line Items]
Current portion of senior notes							$ 25,000,000.0
Credit Agreement
Debt Instrument [Line Items]
Credit facility, outstanding amount			481,300,000	529,400,000
Number of extension periods \| extension	2
Extension period	1 year
Unsecured revolving credit facility										$ 1,350,000,000.0
Unsecured Senior Notes
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage									4.20%
Debt instrument, face amount									$ 500,000,000.0
Outstanding debt balance			500,000,000.0
Term Loan
Debt Instrument [Line Items]
Credit facility, outstanding amount	$ 550,000,000.0
Debt Instrument, Periodic Payment, Principal		$ 67,500,000
Revolving Credit Facility
Debt Instrument [Line Items]
Credit facility, outstanding amount	$ 375,000,000.0								$ 475,000,000.0
Proceeds from lines of credit				0
Uncommitted Facility \| New Master Agreement
Debt Instrument [Line Items]
Credit facility, outstanding amount				$ 0
Master Agreement
Debt Instrument [Line Items]
Unsecured senior notes outstanding			$ 100,000,000.0
Master Agreement \| Series C
Debt Instrument [Line Items]
Unsecured senior notes outstanding												$ 25,000,000.0	$ 25,000,000.0
Debt instrument interest rate stated percentage													5.66%
Master Agreement \| Series D
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage												5.37%
Master Agreement \| Series E
Debt Instrument [Line Items]
Unsecured senior notes outstanding											$ 100,000,000.0
Debt instrument interest rate stated percentage											4.50%
LIBOR
Debt Instrument [Line Items]
30-day Adjusted LIBOR Rate			1.625%
Minimum \| Revolving Credit Facility
Debt Instrument [Line Items]
Facility fee			0.15%
Minimum \| LIBOR \| Term Loan
Debt Instrument [Line Items]
Debt instrument, variable interest rate			1.00%
Minimum \| LIBOR \| Revolving Credit Facility
Debt Instrument [Line Items]
Debt instrument, variable interest rate			0.85%
Maximum \| Revolving Credit Facility
Debt Instrument [Line Items]
Facility fee			0.25%
Maximum \| LIBOR \| Term Loan
Debt Instrument [Line Items]
Debt instrument, variable interest rate			1.75%
Maximum \| LIBOR \| Revolving Credit Facility
Debt Instrument [Line Items]
Debt instrument, variable interest rate			1.50%
Scenario, Forecast [Member]
Debt Instrument [Line Items]
Unsecured senior notes outstanding					$ 5,000,000.0

Long-Term Debt Details (Details) - USD ($) $ in Thousands	12 Months Ended
Long-Term Debt Details (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Debt Disclosure [Abstract]
Interest	$ 36,172	$ 37,652	$ 37,542
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	120,000
Long-term Debt, Maturities, Repayments of Principal in Year Two	30,000
Long-term Debt, Maturities, Repayments of Principal in Year Three	40,000
Long-term Debt, Maturities, Repayments of Principal in Year Four	40,000
Long-term Debt, Maturities, Repayments of Principal in Year Five	255,000
Long-term Debt, Maturities, Repayments of Principal after Year Five	$ 500,000

Income Taxes (Details) - USD ($)	12 Months Ended
Income Taxes (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2013
Income Tax Contingency [Line Items]
Operating Loss Carryforwards State	$ 52,200,000
Operating Loss Carryforwards	100,000
Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities	(126,000)	$ (205,000)	$ (302,000)
Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions	0	(41,000)	0
Deferred Tax Assets, Valuation Allowance	(893,000)	(700,000)
Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions	1,070,000	412,000	773,000
Deferred income taxes, net	256,185,000	357,686,000
Deferred Tax Assets, Operating Loss Carryforwards	2,434,000	2,394,000
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Employee Compensation	36,701,000	44,912,000
Liability for Uncertain Tax Positions, Current	228,608	86,191	102,171
Income Taxes Paid	$ 152,024,000	143,111,000	132,874,000
Document Period End Date	Dec. 31, 2017
Unrecognized Tax Benefits	$ 1,694,000	750,258	$ 583,977	$ 113,000
Deferred Tax Liabilities, Property, Plant and Equipment	2,723,000	6,425,000
deferred profit sharing contingent commissions	$ 7,107,000	$ 10,567,000
Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount	35.00%	35.00%	35.00%
Current Federal Tax Expense (Benefit)	$ 129,954,000	$ 126,145,000	$ 118,490,000
Current State and Local Tax Expense (Benefit)	21,392,000	21,110,000	17,625,000
Current Foreign Tax Expense (Benefit)	929,000	590,000	430,000
Deferred Federal Income Tax Expense (Benefit)	18,999,000	15,551,000	18,416,000
Current Income Tax Expense (Benefit)	152,275,000	147,845,000	136,545,000
Deferred State and Local Income Tax Expense (Benefit)	2,984,000	2,612,000	4,280,000
Deferred Foreign Income Tax Expense (Benefit)	$ 0	0	0
Deferred Foreign Income Tax Expense (Benefit)	As of December 31, 2017, the Company has estimated $20.9 million of cash and cash equivalent balances related to accumulated earnings associated with our international operations.
Summary of Income Tax Contingencies [Table Text Block]	$ (102,183,000)	18,163,000	22,696,000
Income Tax Expense (Benefit)	$ (50,092,000)	$ (166,008,000)	$ (159,241,000)
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent	3.80%	3.90%	3.90%
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-based Compensation Cost, Percent	0.30%	0.30%	0.30%
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Meals and Entertainment, Percent	0.30%	0.30%	0.30%
Tax Reform Act Deferred Tax Revaluation and Transition Tax Impact	(26.90%)
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Other, Percent	(1.40%)	(0.30%)	0.10%
Effective Income Tax Rate Reconciliation, Percent	11.10%	39.20%	39.60%
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals	$ 7,534,000	$ 14,032,000
Net Unrealized Holding Gain on Available for Sale Securities	(6,000)	(12,000)
Deferred Tax Liabilities, Goodwill and Intangible Assets	306,351,000	422,478,000
Non Current Deferred Tax Liability	309,068,000	428,891,000
Deferred Tax Assets, Net, Noncurrent	$ 52,883,000	$ 71,205,000

Income Taxes Effective Income Tax Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Contingency [Line Items]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	35.00%	35.00%	35.00%
Income Tax Expense (Benefit)	$ (50,092)	$ (166,008)	$ (159,241)
Tax Cuts and Jobs Act 2017 [Member]
Income Tax Contingency [Line Items]
Other Tax Expense (Benefit)	$ 3,200
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%
Income Tax Expense (Benefit)	$ 120,900
Taxes Payable	3,300
Deferred Tax Liabilities, Deferred Expense	$ 124,166

Employee Savings Plan (Details) - USD ($)	12 Months Ended
Employee Savings Plan (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Employee Savings Plan [Abstract]
Compensation and Employee Benefit Plans [Text Block]	Employee Savings PlanThe Company has an Employee Savings Plan (401(k)) in which substantially all employees with more than 30 days of service are eligible to participate. Under this plan, Brown & Brown makes matching contributions of up to 4.0% of each participant’s annual compensation. Prior to 2014, the Company’s matching contribution was up to 2.5% of each participant’s annual compensation with an additional discretionary profit-sharing contribution each year, which equaled 1.5% of each eligible employee’s compensation. The Company’s contributions to the plan totaled $19.6 million in 2017, $19.3 million in 2016 and $17.8 million in 2015.
Service Period Eligible to Participate for Employee Savings Plan	$ 30
Defined Contribution Plan, Employer Matching Contribution, Percent of Match	4.00%		2.50%
Discretionary Profit Sharing Contribution Percentage of Employees Salary	1.50%
Defined Benefit Plan, Contributions by Employer	$ 19,600,000	$ 19,300,000	$ 17,800,000

Stock Based Compensation (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	12 Months Ended
	Jul. 31, 2009	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Apr. 28, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price		$ 0	$ 18.48	$ 18.48	$ 18.57
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number		0	175,000	269,589	470,356
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term			1 year 2 months 12 days	2 years 2 months 12 days	3 years 1 month 6 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number		0	175,000	164,589
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period		0	0	0
MaximumNumberOfSharesAvailableToBeGrantedUnderAwardStockPlan		14,400,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross		5,156,954
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant		0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value		$ 6.3	$ 18.1	$ 6.8
IncrementalIncreasesInAverageStockPriceFromInitialGrantPrice		20.00%
Share-based Compensation Arrangement by Share-based Payment Award, Award Requisite Service Period	20 years	15 years
AttainmentAgeOfStockPlan		attainment of age 64
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAwardedSharesOutstandingNumber		847,238
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsDistributedSharesOutstandingNumber		4,309,716
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit		$ 15.58
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit		$ 25.68
PerformanceStockPlan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodAwardedShares		138,801	506,422	208,889
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period		(17,236)	(92,517)	(117,528)
ShareBasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAwardedInPeriod		0	4,000	0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period		0	0	0
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodPriorYearAwardsIssuedGrantedInCurrentYear		0	0	0
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsNotYetAwardedInPeriod		0	0	0
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAwardedInPeriodWeightedAverageGrantDateFairValue		0	0	0
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNotYetAwardedInPeriod		0	(4,000)	0
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageGrantDateFairValue		10.32	10.23	9.03	8.71
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value		$ 9.61	$ 6.39	$ 5.55
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period		(138,801)	(506,422)	(208,889)
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriodAwardedShares		(17,236)	(88,517)	(100,110)
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriodNotYetAwardedShares		0	(4,000)	(17,418)
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodSharesNotAwarded		0	0	0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value		$ 10.47	$ 10.52	$ 9.78
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantedSharesOutstandingNumber		847,238	1,003,275	1,602,214	1,928,631
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsSharesNotYetAwardedOutstandingNumber		0	0	8,000	25,418
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value		$ 0	$ 0	$ 0
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAwardedSharesOutstandingNumber		847,238	1,003,275	1,594,214	1,903,213
Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodAwardedShares		(242,457)	166,884	0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period		(171,060)	(954,131)	(863,241)
ShareBasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAwardedInPeriod		163,404	1,431,319	0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period		696,456	972,099	481,166
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodPriorYearAwardsIssuedGrantedInCurrentYear		120,667	182,653	164,646
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsNotYetAwardedInPeriod				316,520
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAwardedInPeriodWeightedAverageGrantDateFairValue		31.44	24.93	0
ShareBasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsGrantedSharesAwardedInPeriod		0	0	0
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNotYetAwardedInPeriod		(163,404)	(1,431,319)	0
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageGrantDateFairValue		31.16	29.96	28.74		28.19
Stock Issued During Period, Shares, Share-based Compensation, Gross			16,860	15,700	11,350
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant		4,197,920
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value		$ 25.22	$ 27.31	$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period		(242,457)	(166,884)	0
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriodAwardedShares		(38,106)	(175,788)	(95,542)
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriodNotYetAwardedShares		(132,954)	(778,343)	(767,699)
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodSharesNotAwarded		0	0	0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value		$ 29.77	$ 25.34	$ 26.32
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantedSharesOutstandingNumber		6,410,995	6,128,056	6,276,972		6,659,047
SharesAvailableForIssuanceUnderStockIncentivePlan							6,046,768
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsSharesNotYetAwardedOutstandingNumber		4,006,193	3,726,762	5,146,978		5,598,157
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value		$ 41.65	$ 35.52	$ 31.74
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAwardedSharesOutstandingNumber		2,404,802	2,401,294	1,129,994		1,060,890
Employee Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized		17,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant		4,151,251

Stock Based Compensation Summary of PSP Activity (Details) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2013
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAwardedSharesOutstandingNumber	847,238
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	0	0	0
Stock Incentive Plan [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageGrantDateFairValue	31.16	29.96	28.74	28.19
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantedSharesOutstandingNumber	6,410,995	6,128,056	6,276,972	6,659,047
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAwardedSharesOutstandingNumber	2,404,802	2,401,294	1,129,994	1,060,890
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsSharesNotYetAwardedOutstandingNumber	4,006,193	3,726,762	5,146,978	5,598,157
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 41.65	$ 35.52	$ 31.74
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	696,456	972,099	481,166
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodPriorYearAwardsIssuedGrantedInCurrentYear	120,667	182,653	164,646
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsNotYetAwardedInPeriod			316,520
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAwardedInPeriodWeightedAverageGrantDateFairValue	31.44	24.93	0
ShareBasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsGrantedSharesAwardedInPeriod	0	0	0
ShareBasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAwardedInPeriod	163,404	1,431,319	0
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNotYetAwardedInPeriod	(163,404)	(1,431,319)	0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value	$ 25.22	$ 27.31	$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	242,457	166,884	0
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodAwardedShares	242,457	(166,884)	0
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodSharesNotAwarded	0	0	0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value	$ 29.77	$ 25.34	$ 26.32
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period	(171,060)	(954,131)	(863,241)
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriodAwardedShares	(38,106)	(175,788)	(95,542)
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriodNotYetAwardedShares	(132,954)	(778,343)	(767,699)
Time-Based [Member] \| Stock Incentive Plan [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Number of Shares	120,667	182,653	164,646
Perfomance Based [Member] \| Stock Incentive Plan [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsNotYetAwardedInPeriod	575,789	789,446	316,520
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNotYetAwardedInPeriod	163,404	1,435,319	0

Stock Based Compensation Stock Incentive Plan (Details) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Apr. 21, 2000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price	$ 0	$ 18.48	$ 18.48
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross	5,156,954
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	0	0	0
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAwardedSharesOutstandingNumber	847,238
PerformanceStockPlan [Member]
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageGrantDateFairValue	10.32	10.23	9.03	8.71
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 0	$ 0	$ 0
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAwardedInPeriodWeightedAverageGrantDateFairValue	0	0	0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value	$ 9.61	$ 6.39	$ 5.55
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value	$ 10.47	$ 10.52	$ 9.78
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantedSharesOutstandingNumber	847,238	1,003,275	1,602,214	1,928,631
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	0	0	0
ShareBasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAwardedInPeriod	0	4,000	0
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNotYetAwardedInPeriod	0	(4,000)	0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	138,801	506,422	208,889
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period	(17,236)	(92,517)	(117,528)
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAwardedSharesOutstandingNumber	847,238	1,003,275	1,594,214	1,903,213
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodPriorYearAwardsIssuedGrantedInCurrentYear	0	0	0
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodAwardedShares	(138,801)	(506,422)	(208,889)
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriodAwardedShares	(17,236)	(88,517)	(100,110)
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsSharesNotYetAwardedOutstandingNumber	0	0	8,000	25,418
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsNotYetAwardedInPeriod	0	0	0
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodSharesNotAwarded	0	0	0
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriodNotYetAwardedShares	0	(4,000)	(17,418)
Stock Incentive Plan [Member]
Stock Issued During Period, Shares, Share-based Compensation, Gross		16,860	15,700	11,350
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageGrantDateFairValue	31.16	29.96	28.74		28.19
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 41.65	$ 35.52	$ 31.74
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAwardedInPeriodWeightedAverageGrantDateFairValue	31.44	24.93	0
ShareBasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsGrantedSharesAwardedInPeriod	0	0	0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value	$ 25.22	$ 27.31	$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value	$ 29.77	$ 25.34	$ 26.32
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantedSharesOutstandingNumber	6,410,995	6,128,056	6,276,972		6,659,047
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	696,456	972,099	481,166
ShareBasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAwardedInPeriod	163,404	1,431,319	0
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNotYetAwardedInPeriod	(163,404)	(1,431,319)	0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	242,457	166,884	0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period	(171,060)	(954,131)	(863,241)
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAwardedSharesOutstandingNumber	2,404,802	2,401,294	1,129,994		1,060,890
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodPriorYearAwardsIssuedGrantedInCurrentYear	120,667	182,653	164,646
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodAwardedShares	242,457	(166,884)	0
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriodAwardedShares	(38,106)	(175,788)	(95,542)
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsSharesNotYetAwardedOutstandingNumber	4,006,193	3,726,762	5,146,978		5,598,157
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsNotYetAwardedInPeriod			316,520
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodSharesNotAwarded	0	0	0
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriodNotYetAwardedShares	(132,954)	(778,343)	(767,699)
Incentive Stock Option Plan [Member] \| Maximum [Member]
Shares held in Employee Stock Option Plan, Suspense Shares						4,800,000
Perfomance Based [Member] \| Stock Incentive Plan [Member]
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNotYetAwardedInPeriod	163,404	1,435,319	0
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsNotYetAwardedInPeriod	575,789	789,446	316,520

Stock Based Compensation Non Cash Stock Based Compensation Expense (Details) - USD ($)
$ in Thousands

12 Months Ended

Dec. 31, 2017

Dec. 31, 2016

Dec. 31, 2015

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan [Table Text Block]

The non-cash stock-based compensation expense for the years ended December 31 is as follows:



(in thousands)	2017		2016		2015
Stock Incentive Plan	$	24,899	$	11,049	$	11,111
Employee Stock Purchase Plan	4,025		3,698		3,430
Performance Stock Plan	1,707		1,305		972
Incentive Stock Option Plan	—		—		—
Total	$	30,631	$	16,052	$	15,513

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Share-based Compensation

$ 30,631

$ 16,052

$ 15,513

Stock Incentive Plan [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Share-based Compensation

24,899

11,049

11,111

PerformanceStockPlan [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Share-based Compensation

1,707

1,305

972

Incentive Stock Option Plan [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Share-based Compensation

Employee Stock [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Share-based Compensation

$ 4,025

$ 3,698

$ 3,430

Stock Based Compensation Share Based Compensation Shares Authorized under Stock Option Plans, Exercise Price Range (Details) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2017
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	175,000	269,589	470,356	0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term	1 year 2 months 12 days	2 years 2 months 12 days	3 years 1 month 6 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price	$ 18.48	$ 18.48	$ 18.57	$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number	175,000	164,589		0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price	$ 18.48	$ 18.48		$ 0
PerformanceStockPlan [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageGrantDateFairValue	10.23	9.03	8.71	10.32

Stock Based Compensation Summary of Stock Options (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	0	175,000	269,589	470,356
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price	$ 0	$ 18.48	$ 18.48	$ 18.57
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term		1 year 2 months 12 days	2 years 2 months 12 days	3 years 1 month 6 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value	$ 0	$ 4,616	$ 2,395	$ 5,087
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	0	0	0
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price	$ 0	$ 0	$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	175,000	64,589	151,767
Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price	$ 18.48	$ 18.48	$ 18.48
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period	0	30,000	49,000
Share-based Compensation Arrangements by Share-based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price	$ 0	$ 18.48	$ 19.36
Share-based Compensation Arrangement by Share-based Payment Award, Options, Expirations in Period	0	0	0
Share-based Compensation Arrangements by Share-based Payment Award, Options, Expirations in Period, Weighted Average Exercise Price	$ 0	$ 0	$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number	0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price	$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value	$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number	0	175,000	164,589
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price	$ 0	$ 18.48	$ 18.48
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term		1 year 2 months 12 days	2 years 2 months 12 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value	$ 0	$ 4,616	$ 2,241
Stock Incentive Plan [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNotYetAwardedInPeriod	(163,404)	(1,431,319)	0
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodPriorYearAwardsIssuedGrantedInCurrentYear	120,667	182,653	164,646
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	696,456	972,099	481,166

Stock Based Compensation Employee Stock Purchase Plan Details (Details)	12 Months Ended
	Dec. 31, 2017 USD ($) shares	Aug. 31, 2017 $ / shares	Jul. 31, 2017 USD ($) $ / shares shares	Dec. 31, 2016 USD ($) shares	Aug. 31, 2016 $ / shares	Jul. 31, 2016 USD ($) $ / shares shares	Dec. 31, 2015 USD ($) shares	Aug. 31, 2015 $ / shares	Jul. 31, 2015 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	0
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Employee Subscription Rate	10.00%
Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	4,197,920
Employee Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	4,151,251
ThresholdPeriodWorkedPerWeekByEmployees	20
AllottedValueMaximum \| $	$ 25,000
ShareBasedCompensationArrangementByShareBasedPaymentAwardSubscriptionPeriodBeginning	--08-01
ShareBasedCompensationArrangementByShareBasedPaymentAwardSubscriptionPeriodEnding	--07-31
Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price of Common Stock, Percent	85.00%
ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentOfMarketPrice	15.00%
ValueOfOneYearStockOptionPercentage	85.00%
EstimatedFairValuePerShareOption \| $ / shares		$ 8.64			$ 7.61			$ 6.43
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period			529,012			514,665			539,389
ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedAggregatePurchaseValue \| $			$ 16,400,000			$ 15,000,000.0			$ 14,400,000
ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedAggregatePurchasePricePerShare \| $ / shares			$ 31.03			$ 29.23			$ 26.62
Shares held in Employee Stock Option Plan, Suspense Shares	217,514			247,023			231,803
CashReceivedFromProceedsByParticipants \| $	$ 8,200,000			$ 7,700,000			$ 6,800,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	17,000,000

Stock Based Compensation Incentive Stock Option Plan (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Apr. 21, 2000
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value	$ 4.7	$ 1.0	$ 2.2
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	0
PerformanceStockPlan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNotYetAwardedInPeriod	0	(4,000)	0
Incentive Stock Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
PercentageOfPreTaxIncome	15.00%
Incentive Stock Option Plan [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestingPeriod	10 years
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	6 years
Shares held in Employee Stock Option Plan, Suspense Shares				4,800,000
Incentive Stock Option Plan [Member] \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestingPeriod	1 year
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	3 years

Stock Based Compensation Unrecognized Compensation Costs (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017 USD ($)
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	$ 87.9
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	3 years 7 months 13 days

Stock Based Compensation Schedule of compensation cost for share-based payment arrangements, allocation of share-based compensation costs by plan (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation	$ 30,631	$ 16,052	$ 15,513
Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation	24,899	11,049	11,111
PerformanceStockPlan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation	1,707	1,305	972
Incentive Stock Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation	$ 0	$ 0	$ 0

Stock Based Compensation Schedule of Share Based Compensation, Stock Options Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Apr. 28, 2010
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross	5,156,954
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAwardedSharesOutstandingNumber	847,238
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	0	175,000	269,589	470,356
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price	$ 0	$ 18.48	$ 18.48	$ 18.57
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term		1 year 2 months 12 days	2 years 2 months 12 days	3 years 1 month 6 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value	$ 0	$ 4,616	$ 2,395	$ 5,087
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	0	0	0
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price	$ 0	$ 0	$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	(175,000)	(64,589)	(151,767)
Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price	$ 18.48	$ 18.48	$ 18.48
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period	0	(30,000)	(49,000)
Share-based Compensation Arrangements by Share-based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price	$ 0	$ 18.48	$ 19.36
Share-based Compensation Arrangement by Share-based Payment Award, Options, Expirations in Period	0	0	0
Share-based Compensation Arrangements by Share-based Payment Award, Options, Expirations in Period, Weighted Average Exercise Price	$ 0	$ 0	$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number	0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price	$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value	$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number	0	175,000	164,589
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price	$ 0	$ 18.48	$ 18.48
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term		1 year 2 months 12 days	2 years 2 months 12 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value	$ 0	$ 4,616	$ 2,241
Stock Incentive Plan [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNotYetAwardedInPeriod	(163,404)	(1,431,319)	0
SharesAvailableForIssuanceUnderStockIncentivePlan						6,046,768
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantedSharesOutstandingNumber	6,410,995	6,128,056	6,276,972		6,659,047
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 41.65	$ 35.52	$ 31.74
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAwardedSharesOutstandingNumber	2,404,802	2,401,294	1,129,994		1,060,890
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsSharesNotYetAwardedOutstandingNumber	4,006,193	3,726,762	5,146,978		5,598,157
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	696,456	972,099	481,166
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsNotYetAwardedInPeriod			316,520
Stock Issued During Period, Shares, Share-based Compensation, Gross		16,860	15,700	11,350
PerformanceStockPlan [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNotYetAwardedInPeriod	0	(4,000)	0
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantedSharesOutstandingNumber	847,238	1,003,275	1,602,214	1,928,631
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 0	$ 0	$ 0
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAwardedSharesOutstandingNumber	847,238	1,003,275	1,594,214	1,903,213
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsSharesNotYetAwardedOutstandingNumber	0	0	8,000	25,418
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	0	0	0
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsNotYetAwardedInPeriod	0	0	0
Perfomance Based [Member] \| Stock Incentive Plan [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNotYetAwardedInPeriod	163,404	1,435,319	0
ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsNotYetAwardedInPeriod	575,789	789,446	316,520

Supplemental Disclosures of Cash Flow Information and Non-Cash Financing and Investing Activities - Significant Non-Cash Investing and Financing Activities (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted Cash and Cash Equivalents	$ 250,705,000	$ 265,637,000	$ 229,753,000
Cash and Cash Equivalents, at Carrying Value	573,383,000	515,646,000	443,420,000
Cash paid during the period for:
Interest	36,172,000	37,652,000	37,542,000
Income taxes	152,024,000	143,111,000	132,874,000
Significant non-cash investing and financing activities
Other payables issued for purchased customer accounts	11,708,000	10,664,000	10,029,000
Estimated acquisition earn-out payables and related charges	6,921,000	4,463,000	36,899,000
Notes Assumed	0	492,000	0
Notes received on the sale of fixed assets and customer accounts	0	22,000	7,755,000
Cash and Cash Equivalents inclusive of Restricted Cash [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and Cash Equivalents, at Carrying Value	$ 824,088,000	$ 781,283,000	$ 673,173,000

Supplemental Disclosures of Cash Flow Information and Non-Cash Financing and Investing Activities Restricted Cash (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash and Cash Equivalents, at Carrying Value	$ 573,383,000	$ 515,646,000	$ 443,420,000
Restricted Cash and Cash Equivalents	250,705,000	265,637,000	229,753,000
Cash and Cash Equivalents inclusive of Restricted Cash [Member]
Cash and Cash Equivalents, at Carrying Value	$ 824,088,000	$ 781,283,000	$ 673,173,000

Commitments and Contingencies (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Operating Leases, Rent Expense	$ 51,000	$ 49,300	$ 46,000
Operating Leases, Future Minimum Payments Due, Next Twelve Months	42,970
Operating Leases, Future Minimum Payments, Due in Two Years	39,005
Operating Leases, Future Minimum Payments, Due in Three Years	34,236
Operating Leases, Future Minimum Payments, Due in Four Years	27,715
Operating Leases, Future Minimum Payments, Due in Five Years	21,996
Operating Leases, Future Minimum Payments, Due Thereafter	44,496
Operating Leases, Future Minimum Payments Due	$ 210,418	$ 213,200

Quarterly Operating Results (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Total revenues	$ 474,316	$ 475,646	$ 466,305	$ 465,080	$ 433,664	$ 462,274	$ 446,518	$ 424,173	$ 1,881,347	$ 1,766,629	$ 1,660,509
Operating Expenses	367,982	351,227	358,303	354,113	338,763	345,302	337,441	321,624	1,431,625	1,343,130	1,257,950
Income before income taxes	106,334	124,419	108,002	110,967	94,901	116,972	109,077	102,549	449,722	423,499	402,559
Net Income (Loss) Attributable to Parent	$ 187,505	$ 75,913	$ 66,102	$ 70,110	$ 57,626	$ 71,545	$ 66,250	$ 62,070	$ 399,630	$ 257,491	$ 243,318
Earnings Per Share, Basic	$ 0.0135	$ 0.0054	$ 0.0047	$ 0.0050	$ 0.0041	$ 0.0051	$ 0.0047	$ 0.0045	$ 2.86	$ 1.84	$ 1.72
Diluted (in dollars per share)	$ 0.0132	$ 0.0053	$ 0.0046	$ 0.0049	$ 0.0041	$ 0.0050	$ 0.0047	$ 0.0044	$ 2.81	$ 1.82	$ 1.70

Segment Information - Additional Information (Detail) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2017 USD ($) Segment	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments \| Segment									4
Total revenues	$ 474,316	$ 475,646	$ 466,305	$ 465,080	$ 433,664	$ 462,274	$ 446,518	$ 424,173	$ 1,881,347	$ 1,766,629	$ 1,660,509
London, Bermuda and Cayman Islands
Segment Reporting Information [Line Items]
Total revenues									$ 15,900	$ 14,500	$ 13,400

Segment Information - Summarized Financial Information Reportable Segments (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Total revenues	$ 474,316	$ 475,646	$ 466,305	$ 465,080	$ 433,664	$ 462,274	$ 446,518	$ 424,173	$ 1,881,347	$ 1,766,629	$ 1,660,509
Investment income									1,626	1,456	1,004
Amortization									85,446	86,663	87,421
Depreciation									22,698	21,003	20,890
Interest expense									38,316	39,481	39,248
Income before income taxes	106,334	$ 124,419	$ 108,002	$ 110,967	94,901	$ 116,972	$ 109,077	$ 102,549	449,722	423,499	402,559
Total assets	5,747,550				5,262,734				5,747,550	5,262,734	4,979,844
Capital expenditures									24,192	17,765	18,375
Operating Segments \| Retail
Segment Reporting Information [Line Items]
Total revenues									943,460	917,406	870,346
Investment income									8	37	87
Amortization									42,164	43,447	45,145
Depreciation									5,210	6,191	6,558
Interest expense									31,133	38,216	41,036
Income before income taxes									196,616	188,001	181,938
Total assets	4,255,515				3,854,393				4,255,515	3,854,393	3,507,476
Capital expenditures									4,494	5,951	6,797
Operating Segments \| National Programs
Segment Reporting Information [Line Items]
Total revenues									479,813	448,516	428,734
Investment income									384	628	210
Amortization									27,277	27,920	28,479
Depreciation									6,325	7,868	7,250
Interest expense									35,561	45,738	55,705
Income before income taxes									109,961	91,762	67,673
Total assets	3,267,486				2,711,378				3,267,486	2,711,378	2,503,537
Capital expenditures									5,936	6,977	6,001
Operating Segments \| Wholesale Brokerage
Segment Reporting Information [Line Items]
Total revenues									271,737	243,103	216,996
Investment income									0	4	150
Amortization									11,456	10,801	9,739
Depreciation									1,885	1,975	2,142
Interest expense									6,263	3,976	891
Income before income taxes									68,844	62,623	64,708
Total assets	1,260,239				1,108,829				1,260,239	1,108,829	895,782
Capital expenditures									1,836	1,301	3,084
Operating Segments \| Services
Segment Reporting Information [Line Items]
Total revenues									165,372	156,365	145,365
Investment income									299	283	42
Amortization									4,548	4,485	4,019
Depreciation									1,600	1,881	1,988
Interest expense									3,522	4,950	5,970
Income before income taxes									30,498	24,338	19,713
Total assets	399,240				371,645				399,240	371,645	285,459
Capital expenditures									1,033	656	1,088
Other
Segment Reporting Information [Line Items]
Total revenues									20,965	1,239	(932)
Investment income									935	504	515
Amortization									1	10	39
Depreciation									7,678	3,088	2,952
Interest expense									(38,163)	(53,399)	(64,354)
Income before income taxes									43,803	56,775	68,527
Total assets	$ (3,434,930)				$ (2,783,511)				(3,434,930)	(2,783,511)	(2,212,410)
Capital expenditures									$ 10,893	$ 2,880	$ 1,405

Losses and Loss Adjustment Reserve - Effects of Reinsurance on Premiums Written and Earned (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Written
Direct premiums	$ 604,623	$ 591,142
Assumed premiums	0	0
Ceded premiums	604,610	591,124
Net premiums	13	18
Earned
Direct premiums	592,267	592,123
Assumed premiums	0	0
Ceded premiums	592,254	592,105
Net premiums	$ 13	$ 18

Losses and Loss Adjustment Reserve - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2017 USD ($) Reinsurer	Dec. 31, 2016 USD ($)
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Ceded rate of premiums under insurance program	100.00%
Document Period End Date	Dec. 31, 2017
Premiums written net	$ 604,610,000	$ 591,124,000
Reinsurance Recoverables on Unpaid Losses, Gross	477,800,000	78,100,000
Prepaid reinsurance premiums	321,017,000	308,661,000
Increase (Decrease) in Loss and Loss Adjustment Expense Reserve	1,100,000
Reserve For Losses And Loss Adjustment Expenses For Reinsurance Liability	$ 477,800,000	78,100,000
Number of reinsurers \| Reinsurer	2
Wright National Flood Insurance Company [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Ceded rate of premiums under insurance program	100.00%
Percentage of reinsurance recoverables allowance	30.90%
Premiums written net	$ 602,900,000	589,500,000
Wright National Flood Insurance Company [Member] \| Quota Share Agreement
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Effective cedes rate under quota share agreement	100.00%
Commission rate, percent of ceded written premiums	30.50%
Wright National Flood Insurance Company [Member] \| Quota Share Agreement \| Reinsurer Concentration Risk [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Ceded amount	$ 1,700,000	$ 1,600,000
Wright National Flood Insurance Company [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Loss Adjustment Expense	16,606
Case Reserves	838,307
Liability for Unpaid Claims and Claims Adjustment Expense, Incurred but Not Reported (IBNR) Claims, Amount	$ 1,500,000

Statutory Financial Information - Additional Information (Detail) - Wright Flood - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Statutory Accounting Practices [Line Items]
Statutory capital and surplus required	$ 7,500,000
Statutory capital and surplus	28,700,000	$ 23,500,000
Statutory net Income	$ 4,800,000	$ 8,200,000

Subsidiary Dividend Restrictions - Additional Information (Detail) - Wright Flood - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2018
Dividend Restrictions [Line Items]
Dividend rate as a percentage of net income	100.00%
Statutory Dividend Payment Restrictions Disclosure	Under the insurance regulations of Texas, where WNFIC in incorporated, the maximum amount of ordinary dividends that WNFIC can pay to shareholders in a rolling twelve month period is limited to the greater of 10% of statutory adjusted capital and surplus as shown on WNFIC’s last annual statement on file with the superintendent of the Texas Department of Insurance or 100% of adjusted net income
Scenario, Forecast
Dividend Restrictions [Line Items]
Maximum dividend payout that may be made without prior approval		$ 4.8
Maximum
Dividend Restrictions [Line Items]
Dividend rate as a percentage of net income	10.00%

Shareholders' Equity - Additional Information (Detail) - USD ($)	12 Months Ended			48 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2017	Feb. 09, 2018	Jul. 20, 2015	Jul. 21, 2014
Accelerated Share Repurchases [Line Items]
Treasury stock shares (in shares)	8,003,197			10,718,319
Fair value of common stock repurchased	$ 257,683,000			$ 386,322,000
Stock Repurchase Program, Remaining Authorized Repurchase Amount				$ 238,700,000
Treasury Stock, Shares, Acquired				10,700,000
Accelerated Share Repurchase Agreement [Member]
Accelerated Share Repurchases [Line Items]
Treasury stock shares (in shares)	209,618	5,408,819	2,384,760	348,460
Treasury Stock Acquired, Average Cost Per Share	$ 36.53	$ 32.35	$ 31.46
Fair value of common stock repurchased	$ 7,700,000	$ 175,000,000.0	$ 75,000,000.0	$ 14,900,000
Second Accelerated Share Repurchase Agreement [Member]
Accelerated Share Repurchases [Line Items]
Treasury stock shares (in shares)				1,076,176
Fair value of common stock repurchased				$ 50,000,000.0
Third Accelerated Share Repurchase Agreement [Member]
Accelerated Share Repurchases [Line Items]
Stock Repurchase Program, Authorized Amount				75,000,000.0
Fair value of common stock repurchased				63,800,000
Maximum [Member]
Accelerated Share Repurchases [Line Items]
Stock Repurchase Program, Authorized Amount				$ 100,000,000.0		$ 400,000,000.0	$ 200,000,000.0
Subsequent Event [Member] \| Third Accelerated Share Repurchase Program [Member]
Accelerated Share Repurchases [Line Items]
Treasury stock shares (in shares)					1,458,713
Fair value of common stock repurchased					$ 11,200,000
Share Repurchase Executed Part 2 [Member] \| Second Accelerated Share Repurchase Agreement [Member]
Accelerated Share Repurchases [Line Items]
Treasury stock shares (in shares)				108,288
Fair value of common stock repurchased				$ 7,500,000
Share Repurchase Executed Part 2 [Member] \| Subsequent Event [Member] \| Third Accelerated Share Repurchase Program [Member]
Accelerated Share Repurchases [Line Items]
Treasury stock shares (in shares)					168,227
Share Repurchase Executed Part 1 [Member] \| Second Accelerated Share Repurchase Agreement [Member]
Accelerated Share Repurchases [Line Items]
Treasury stock shares (in shares)				967,888
Fair value of common stock repurchased				$ 42,500,000
Share Repurchase Executed Part 1 [Member] \| Third Accelerated Share Repurchase Agreement [Member]
Accelerated Share Repurchases [Line Items]
Treasury stock shares (in shares)				1,290,486

Statutory Financial Information	12 Months Ended
Statutory Financial Information	Dec. 31, 2017
Statutory Accounting Practices [Abstract]
Statutory Financial Information	Statutory Financial InformationWNFIC maintains capital in excess of minimum statutory amount of $7.5 million as required by regulatory authorities. The statutory capital and surplus of WNFIC was $28.7 million as of December 31, 2017 and $23.5 million as of December 31, 2016. As of December 31, 2017 and 2016, WNFIC generated statutory net income of $4.8 million and $8.2 million, respectively.

Subsidiary Dividend Restrictions	12 Months Ended
Subsidiary Dividend Restrictions	Dec. 31, 2017
Disclosure of Restrictions on Dividends, Loans and Advances Disclosure [Abstract]
Subsidiary Dividend Restrictions	Subsidiary Dividend RestrictionsUnder the insurance regulations of Texas, where WNFIC in incorporated, the maximum amount of ordinary dividends that WNFIC can pay to shareholders in a rolling twelve month period is limited to the greater of 10% of statutory adjusted capital and surplus as shown on WNFIC’s last annual statement on file with the superintendent of the Texas Department of Insurance or 100% of adjusted net income. There was no dividend payout in 2017 and the maximum dividend payout that may be made in 2018 without prior approval is $4.8 million.

Summary of Significant Accounting Policies Fair Value of Financial Instruments (Details) $ in Millions	Dec. 31, 2017 USD ($)
Text Block [Abstract]
Long-term Debt, Fair Value	$ 598.9

Summary of Significant Accounting Policies Amortizable Intangible Assets (Details)	12 Months Ended
	Dec. 31, 2017
Minimum
Indefinite-lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	3 years
Maximum
Indefinite-lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	15 years

Nature of Operations - Additional Information (Detail)	12 Months Ended
Nature of Operations - Additional Information (Detail)	Dec. 31, 2017 Segment
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of reportable segments	4

Fixed Income Securities (Details) $ in Millions	12 Months Ended
Fixed Income Securities (Details) $ in Millions	Dec. 31, 2016 USD ($)
Schedule of Available-for-sale Securities [Line Items]
Proceeds from Sale of Short-term Investments	$ 1.7