CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash flows from operating activities:
Net income	$ 152,400	$ 113,896
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization	26,391	26,192
Depreciation	6,021	6,035
Non-cash stock-based compensation	9,047	12,994
Change in estimated acquisition earn-out payables	(10,957)	1,210
Deferred income taxes	(4,974)	(14,875)
Amortization of debt discount and disposal of deferred financing costs	512	456
Accretion (amortization) of discounts and premiums, investment	7	(7)
Net gain/(loss) on sales of investments, fixed assets and customer accounts	(196)	799
Payments on acquisition earn-outs in excess of original estimated payables	(337)
Changes in operating assets and liabilities, net of effect from acquisitions and divestitures:
Premiums, commissions and fees receivable (increase) decrease	(53,090)	(6,484)
Reinsurance recoverables (increase) decrease	24,949	14,040
Prepaid reinsurance premiums (increase) decrease	32,215	23,557
Other assets (increase) decrease	24,623	(29,521)
Premiums payable to insurance companies increase (decrease)	(53,622)	(61,229)
Premium deposits and credits due customers increase (decrease)	13,149	(11,362)
Losses and loss adjustment reserve increase (decrease)	(24,952)	(13,856)
Unearned premiums increase (decrease)	(32,215)	(23,557)
Accounts payable increase (decrease)	56,981	56,436
Accrued expenses and other liabilities increase (decrease)	(126,786)	(97,689)
Other liabilities increase (decrease)	(5,349)	8,321
Net cash provided by operating activities	33,817	5,356
Cash flows from investing activities:
Additions to fixed assets	(16,458)	(23,186)
Payments for businesses acquired, net of cash acquired	(153,291)	(95,081)
Proceeds from sales of fixed assets and customer accounts	385	32
Purchases of investments	(1,513)	(31)
Proceeds from sales of investments	1,668	2,392
Net cash used in investing activities	(169,209)	(115,874)
Cash flows from financing activities:
Payments on acquisition earn-outs	(6,477)	(579)
Proceeds from long-term debt		350,000
Payments on long-term debt	(13,750)	(8,750)
Deferred debt issuance costs		(3,698)
Payments on revolving credit facilities		(350,000)
Issuances of common stock for employee stock benefit plans		16
Repurchase shares to fund tax withholdings for non-cash stock-based compensation	(6,847)	(6,832)
Purchase of treasury stock	(1,429)
Cash dividends paid	(23,902)	(22,348)
Net cash provided by (used in) financing activities	(52,405)	(42,191)
Net increase (decrease) in cash and cash equivalents inclusive of restricted cash	(187,797)	(152,709)
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	$ 775,178	$ 624,887