Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Cash flows from operating activities
Net income	$ 1,239	$ 982
Adjustments to reconcile net income to cash provided by operating activities:
Gain from sales of businesses	(20)	0
Depreciation of fixed assets	46	46
Amortization and impairment of intangible assets	152	199
Share-based compensation expense	82	147
Deferred income taxes	(49)	(117)
Other, net	1	(17)
Change in assets and liabilities:
Receivables, net	(905)	(742)
Accounts payable and accrued liabilities	(656)	(846)
Accelerating Aon United Program liabilities	14	(6)
Current income taxes	243	152
Pension, other postretirement and postemployment liabilities	(14)	(8)
Other assets and liabilities	297	350
Cash provided by operating activities	430	140
Cash flows from investing activities
Proceeds from investments	17	20
Purchases of investments	(19)	(19)
Net sale (purchases) of short-term investments - non fiduciary	1,363	(145)
Acquisition of businesses, net of cash and funds held on behalf of clients	(296)	(116)
Sale of businesses, net of cash and funds held on behalf of clients	1	24
Capital expenditures	(67)	(56)
Cash provided by (used for) investing activities	999	(292)
Cash flows from financing activities
Share repurchase	(500)	(250)
Proceeds from issuance of shares	25	30
Cash paid for employee taxes on withholding shares	(93)	(141)
Commercial paper issuances, net of repayments	0	594
Repayment of debt	(593)	0
Increase (decrease) in fiduciary liabilities, net of fiduciary receivables	955	(355)
Cash dividends to shareholders	(162)	(147)
Redeemable and nonredeemable noncontrolling interests, and other financing activities	(73)	(80)
Cash used for financing activities	(441)	(349)
Effect of exchange rates on cash and cash equivalents and funds held on behalf of clients	(97)	196
Net increase (decrease) in cash and cash equivalents and funds held on behalf of clients	891	(305)
Cash, cash equivalents and funds held on behalf of clients at beginning of period	8,573	8,333
Cash, cash equivalents and funds held on behalf of clients at end of period	9,464	8,028
Reconciliation of cash and cash equivalents and funds held on behalf of clients:
Cash and cash equivalents	1,178	964
Cash and cash equivalents and funds held on behalf of clients classified as held for sale	0	2
Funds held on behalf of clients	8,286	7,062
Total cash and cash equivalents and funds held on behalf of clients	9,464	8,028
Supplemental disclosures:
Interest paid	271	273
Income taxes paid, net of refunds	$ 120	$ 233