CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities:
Net income before non-controlling interests	$ 1,002	$ 871	$ 672
Adjustments to reconcile net income before non-controlling interests to net cash provided by operating activities:
Amortization	178	166	147
Depreciation	44	40	39
Non-cash stock-based compensation	101	89	66
Change in estimated acquisition earn-out payables	2	21	(39)
Deferred income taxes	13	12	43
Net gain on sales/disposals of investments, businesses, fixed assets and customer accounts	(29)	(140)	(4)
Payments on acquisition earn-outs in excess of original estimated payables	(37)	(29)	(30)
Other	5	5	3
Changes in operating assets and liabilities, net of effect from acquisitions and divestitures:
Commissions, fees and other receivables (increase) decrease	(94)	(106)	(61)
Reinsurance recoverable (increase) decrease	(1,402)	706	(768)
Prepaid reinsurance premiums (increase) decrease	(58)	(68)	(1)
Other assets (increase) decrease	(98)	(117)	(18)
Losses and loss adjustment reserve increase (decrease)	1,411	(710)	778
Unearned premiums increase (decrease)	115	50	20
Accounts payable increase (decrease)	(47)	260	124
Accrued expenses and other liabilities increase (decrease)	35	43	37
Other liabilities increase (decrease)	33	(83)	(127)
Net cash provided by operating activities	1,174	1,010	881
Cash flows from investing activities:
Additions to fixed assets	(82)	(69)	(52)
Payments for businesses acquired, net of cash acquired	(890)	(631)	(1,928)
Proceeds from sales of businesses, fixed assets and customer accounts	70	107	60
Purchases of investments	(7)	(7)
Proceeds from sales of investments	11	13	7
Net cash used in investing activities	(898)	(587)	(1,913)
Cash flows from financing activities:
Fiduciary receivables and liabilities, net	191	189	96
Payments on acquisition earn-outs	(117)	(90)	(76)
Proceeds from long-term debt	599		2,000
Payments on long-term debt	(719)	(251)	(61)
Deferred debt issuance costs	(5)		(23)
Borrowings on revolving credit facility	500	420	350
Payments on revolving credit facilities	(350)	(320)	(350)
Issuances of common stock for employee stock benefit plans	44	40	38
Repurchase shares to fund tax withholdings for non-cash stock-based compensation	(55)	(40)	(49)
Purchase of treasury stock			(74)
Cash dividends paid	(154)	(135)	(120)
Other financing activities	2		(5)
Net cash (used in) provided by financing activities	(64)	(187)	1,726
Effect of foreign exchange rate changes on cash and cash equivalents inclusive of fiduciary cash	(13)	34	(131)
Net increase in cash and cash equivalents inclusive of fiduciary cash	199	270	563
Cash and cash equivalents inclusive of fiduciary cash at beginning of period	2,303	2,033	1,470
Cash and cash equivalents inclusive of fiduciary cash at end of period	$ 2,502	$ 2,303	$ 2,033