Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Cash flows from operating activities
Net income	$ 3,750	$ 2,720	$ 2,628
Adjustments to reconcile net income to cash provided by operating activities:
Gain from sales of businesses	(1,201)	(337)	(4)
Depreciation of fixed assets	188	183	167
Amortization and impairment of intangible assets	778	503	89
Share-based compensation expense	432	474	438
Deferred income taxes	(141)	(311)	(373)
Other, net	(133)	(134)	28
Change in assets and liabilities:
Receivables, net	(257)	(312)	(188)
Accounts payable and accrued liabilities	(155)	393	13
Accelerating Aon United Program liabilities	27	17	99
Current income taxes	114	0	174
Pension, other postretirement and postemployment liabilities	(16)	(18)	8
Other assets and liabilities	95	(143)	356
Cash provided by operating activities	3,481	3,035	3,435
Cash flows from investing activities
Proceeds from investments	145	212	76
Purchases of investments	(172)	(172)	(67)
Net sales (purchases) of short-term investments - non fiduciary	(1,379)	151	85
Acquisition of businesses, net of cash and funds held on behalf of clients	(394)	(3,506)	(35)
Sale of businesses, net of cash and funds held on behalf of clients	2,349	700	5
Capital expenditures	(263)	(218)	(252)
Cash provided by (used for) investing activities	286	(2,833)	(188)
Cash flows from financing activities
Share repurchase	(1,000)	(1,000)	(2,700)
Proceeds from issuance of shares	70	79	72
Cash paid for employee taxes on withholding shares	(208)	(202)	(241)
Commercial paper issuances, net of repayments	(24)	(591)	(27)
Issuance of debt	0	7,926	744
Repayment of debt	(1,850)	(4,928)	(350)
Increase in fiduciary liabilities, net of fiduciary receivables	(366)	280	358
Cash dividends to shareholders	(629)	(562)	(489)
Redeemable and nonredeemable noncontrolling interests, and other financing activities	(198)	(206)	(232)
Cash provided by (used for) financing activities	(4,205)	796	(2,865)
Effect of exchange rates on cash and cash equivalents and funds held on behalf of clients	678	(387)	264
Net increase in cash and cash equivalents and funds held on behalf of clients	240	611	646
Cash, cash equivalents and funds held on behalf of clients at beginning of year	8,333	7,722	7,076
Cash, cash equivalents and funds held on behalf of clients at end of year	8,573	8,333	7,722
Reconciliation of cash and cash equivalents and funds held on behalf of clients:
Cash and cash equivalents	1,195	1,085	778
Cash and cash equivalents and funds held on behalf of clients classified as held for sale	0	1	43
Funds held on behalf of clients	7,378	7,247	6,901
Total cash and cash equivalents and funds held on behalf of clients	$ 8,573	$ 8,333	$ 7,722