Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Cash flows from operating activities
Net income	$ 2,046	$ 1,986
Adjustments to reconcile net income to cash provided by operating activities:
Gain from sales of businesses	(1)	(333)
Depreciation of fixed assets	140	136
Amortization and impairment of intangible assets	593	318
Share-based compensation expense	372	361
Deferred income taxes	(236)	(146)
Other, net	(116)	(126)
Change in assets and liabilities:
Receivables, net	(342)	(384)
Accounts payable and accrued liabilities	(543)	(36)
Accelerating Aon United Program liabilities	(29)	43
Current income taxes	(141)	(119)
Pension, other postretirement and postemployment liabilities	(17)	(25)
Other assets and liabilities	358	160
Cash provided by operating activities	2,084	1,835
Cash flows from investing activities
Proceeds from investments	114	186
Purchases of investments	(139)	(136)
Net purchases of short-term investments - non fiduciary	16	182
Acquisition of businesses, net of cash and funds held on behalf of clients	(276)	(3,011)
Sale of businesses, net of cash and funds held on behalf of clients	112	686
Capital expenditures	(189)	(163)
Cash used for investing activities	(362)	(2,256)
Cash flows from financing activities
Share repurchase	(750)	(800)
Proceeds from issuance of shares	60	61
Cash paid for employee taxes on withholding shares	(201)	(190)
Commercial paper issuances, net of repayments	376	(591)
Issuance of debt	0	7,926
Repayment of debt	(700)	(4,878)
Increase in fiduciary liabilities, net of fiduciary receivables	706	609
Cash dividends to shareholders	(468)	(416)
Redeemable and nonredeemable noncontrolling interests, and other financing activities	(164)	(156)
Cash provided by (used for) financing activities	(1,141)	1,565
Effect of exchange rates on cash and cash equivalents and funds held on behalf of clients	606	177
Net increase in cash and cash equivalents and funds held on behalf of clients	1,187	1,321
Cash, cash equivalents and funds held on behalf of clients at beginning of period	8,333	7,722
Cash, cash equivalents and funds held on behalf of clients at end of period	9,520	9,043
Reconciliation of cash and cash equivalents and funds held on behalf of clients:
Cash and cash equivalents	1,095	1,103
Cash and cash equivalents and funds held on behalf of clients classified as held for sale	34	0
Funds held on behalf of clients	8,391	7,940
Total cash and cash equivalents and funds held on behalf of clients	9,520	9,043
Supplemental disclosures:
Interest paid	689	538
Income taxes paid, net of refunds	$ 881	$ 850