CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Cash flows from operating activities:
Net income	$ 249,184	$ 206,489
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization	53,132	52,146
Depreciation	12,189	11,701
Non-cash stock-based compensation	30,087	24,128
Change in estimated acquisition earn-out payables	(10,322)	(1,650)
Deferred income taxes	(4,766)	(5,342)
Amortization of debt discount and disposal of deferred financing costs	1,066	988
Accretion (amortization) of discounts and premiums, investment	14	(12)
Net gain/(loss) on sales of investments, fixed assets and customer accounts	86	(346)
Payments on acquisition earn-outs in excess of original estimated payables	(576)	(267)
Changes in operating assets and liabilities, net of effect from acquisitions and divestitures:
Premiums, commissions and fees receivable (increase) decrease	(130,110)	(71,614)
Reinsurance recoverables (increase) decrease	13,295	(11,939)
Prepaid reinsurance premiums (increase) decrease	9,201	(5,674)
Other assets (increase) decrease	(2,691)	(22,122)
Premiums payable to insurance companies increase (decrease)	177,685	116,472
Premium deposits and credits due customers increase (decrease)	(12,103)	(12,003)
Losses and loss adjustment reserve increase (decrease)	(13,295)	12,123
Unearned premiums increase (decrease)	(9,201)	5,674
Accounts payable increase (decrease)	101,124	23,773
Accrued expenses and other liabilities increase (decrease)	(47,742)	(32,269)
Other liabilities increase (decrease)	442	15,447
Net cash provided by operating activities	416,699	305,703
Cash flows from investing activities:
Additions to fixed assets	(35,938)	(35,174)
Payments for businesses acquired, net of cash acquired	(291,424)	(146,646)
Proceeds from sales of fixed assets and customer accounts	295	2,101
Purchases of investments	(3,031)	(9,265)
Proceeds from sales of investments	3,669	4,505
Net cash used in investing activities	(326,429)	(184,479)
Cash flows from financing activities:
Payments on acquisition earn-outs	(6,902)	(6,997)
Proceeds from long-term debt		350,000
Payments on long-term debt	(27,500)	(22,500)
Deferred debt issuance costs		(3,701)
Borrowings on revolving credit facility	250,000
Payments on revolving credit facilities	(150,000)	(350,000)
Issuances of common stock for employee stock benefit plans	587	901
Repurchase shares to fund tax withholdings for non-cash stock-based compensation	(7,811)	(6,861)
Purchase of treasury stock	(1,429)	(20,000)
Settlement (prepayment) of accelerated share repurchase program		20,000
Cash dividends paid	(47,986)	(44,881)
Net cash provided by (used in) financing activities	8,959	(84,039)
Net increase in cash and cash equivalents inclusive of restricted cash	99,229	37,185
Cash and cash equivalents inclusive of restricted cash at beginning of period	962,975	777,596
Cash and cash equivalents inclusive of restricted cash at end of period	$ 1,062,204	$ 814,781