Condensed Consolidated Statements of Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Revenue
Total revenue	$ 4,155	$ 3,760	$ 8,884	$ 7,830
Expenses
Compensation and benefits	2,360	2,130	4,609	4,013
Information technology	136	132	272	256
Premises	85	82	167	153
Depreciation of fixed assets	47	45	93	89
Amortization and impairment of intangible assets	201	128	400	144
Other general expense	373	455	819	803
Accelerating Aon United Program expenses	94	132	204	251
Total operating expenses	3,296	3,104	6,564	5,709
Operating income	859	656	2,320	2,121
Interest income	0	31	5	59
Interest expense	(212)	(225)	(418)	(369)
Other income (expense)	56	236	46	311
Income before income taxes	703	698	1,953	2,122
Income tax expense	109	160	377	491
Net income	594	538	1,576	1,631
Less: Net income attributable to redeemable and nonredeemable noncontrolling interests	15	14	32	36
Net income attributable to Aon shareholders	$ 579	$ 524	$ 1,544	$ 1,595
Basic net income per share attributable to Aon shareholders (in dollars per share)	$ 2.68	$ 2.47	$ 7.14	$ 7.75
Diluted net income per share attributable to Aon shareholders (in dollars per share)	$ 2.66	$ 2.46	$ 7.10	$ 7.72
Weighted average ordinary shares outstanding - basic (in shares)	216.2	212.5	216.3	205.8
Weighted average ordinary shares outstanding - diluted (in shares)	217.3	213.3	217.6	206.7