CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities:
Net income	$ 199,744	$ 152,400
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization	29,493	26,391
Depreciation	7,456	6,021
Non-cash stock-based compensation	18,678	9,047
Change in estimated acquisition earn-out payables	(890)	(10,957)
Deferred income taxes	10,569	(4,974)
Amortization of debt discount and disposal of deferred financing costs	694	512
Amortization (accretion) of discounts and premiums, investment	31	7
Net (gain)/loss on sales of investments, fixed assets and customer accounts	(378)	(196)
Payments on acquisition earn-outs in excess of original estimated payables	(354)	(337)
Effect of foreign exchange rate changes	245
Changes in operating assets and liabilities, net of effect from acquisitions and divestitures:
Premiums, commissions and fees receivable (increase) decrease	(22,036)	(53,090)
Reinsurance recoverables (increase) decrease	17,179	24,949
Prepaid reinsurance premiums (increase) decrease	32,584	32,215
Other assets (increase) decrease	25,253	24,623
Premiums payable to insurance companies increase (decrease)	(103,841)	(53,622)
Premium deposits and credits due customers increase (decrease)	25,908	13,149
Losses and loss adjustment reserve increase (decrease)	(17,179)	(24,952)
Unearned premiums increase (decrease)	(32,584)	(32,215)
Accounts payable increase (decrease)	68,874	56,981
Accrued expenses and other liabilities increase (decrease)	(106,994)	(126,786)
Other liabilities increase (decrease)	(27,344)	(5,349)
Net cash provided by operating activities	125,108	33,817
Cash flows from investing activities:
Additions to fixed assets	(11,425)	(16,458)
Payments for businesses acquired, net of cash acquired	(70,429)	(153,291)
Proceeds from sales of fixed assets and customer accounts	182	385
Purchases of investments	(5,098)	(1,513)
Proceeds from sales of investments	4,376	1,668
Net cash used in investing activities	(82,394)	(169,209)
Cash flows from financing activities:
Payments on acquisition earn-outs	(15,121)	(6,477)
Payments on long-term debt	(17,500)	(13,750)
Repurchase shares to fund tax withholdings for non-cash stock-based compensation	(45,052)	(6,847)
Purchase of treasury stock	(70,020)	(1,429)
Cash dividends paid	(26,092)	(23,902)
Net cash used in financing activities	(173,785)	(52,405)
Effect of foreign exchange rate cash changes	(120)
Net decrease in cash and cash equivalents inclusive of restricted cash	(131,191)	(187,797)
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	$ 1,140,724	$ 775,178