CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash flows from operating activities:
Net income	$ 339,033	$ 249,184
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization	59,039	53,132
Depreciation	16,257	12,189
Non-cash stock-based compensation	32,723	30,087
Change in estimated acquisition earn-out payables	(2,495)	(10,322)
Deferred income taxes	21,933	(4,766)
Amortization of debt discount and disposal of deferred financing costs	144	1,066
Amortization (accretion) of discounts and premiums, investment	1,316	14
Net (gain)/loss on sales of investments, fixed assets and customer accounts	(2,859)	86
Payments on acquisition earn-outs in excess of original estimated payables	(5,747)	(576)
Effect of changes in foreign exchange rate changes	577
Changes in operating assets and liabilities, net of effect from acquisitions and divestitures:
Premiums, commissions and fees receivable (increase) decrease	(120,854)	(130,110)
Reinsurance recoverables (increase) decrease	1,055	13,295
Prepaid reinsurance premiums (increase) decrease	8,904	9,201
Other assets (increase) decrease	(35,578)	(2,691)
Premiums payable to insurance companies increase (decrease)	141,074	177,685
Premium deposits and credits due customers increase (decrease)	5,265	(12,103)
Losses and loss adjustment reserve increase (decrease)	(1,055)	(13,295)
Unearned premiums increase (decrease)	(8,904)	(9,201)
Accounts payable increase (decrease)	65,212	101,124
Accrued expenses and other liabilities increase (decrease)	(21,295)	(47,742)
Other liabilities increase (decrease)	(27,478)	442
Net cash provided by operating activities	466,267	416,699
Cash flows from investing activities:
Additions to fixed assets	(25,142)	(35,938)
Payments for businesses acquired, net of cash acquired	(116,618)	(291,424)
Proceeds from sales of fixed assets and customer accounts	8,298	295
Purchases of investments	(9,754)	(3,031)
Proceeds from sales of investments	6,910	3,669
Net cash used in investing activities	(136,306)	(326,429)
Cash flows from financing activities:
Payments on acquisition earn-outs	(34,202)	(6,902)
Payments on long-term debt	(35,000)	(27,500)
Borrowings on revolving credit facility		250,000
Payments on revolving credit facilities		(150,000)
Issuances of common stock for employee stock benefit plans	903	587
Repurchase shares to fund tax withholdings for non-cash stock-based compensation	(48,256)	(7,811)
Purchase of treasury stock	(81,425)	(1,429)
Cash dividends paid	(52,155)	(47,986)
Net cash (used in) provided by financing activities	(250,135)	8,959
Effect of foreign exchange rate cash changes	(721)
Net increase in cash and cash equivalents inclusive of restricted cash	79,105	99,229
Cash and cash equivalents inclusive of restricted cash at beginning of period	1,271,915	962,975
Cash and cash equivalents inclusive of restricted cash at end of period	$ 1,351,020	$ 1,062,204