Condensed Consolidated Statements of Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Revenue
Total revenue	$ 3,760	$ 3,177	$ 7,830	$ 7,048
Expenses
Compensation and benefits	2,130	1,754	4,013	3,546
Information technology	132	129	256	268
Premises	82	68	153	143
Depreciation of fixed assets	45	39	89	77
Amortization and impairment of intangible assets	128	25	144	50
Other general expense	455	320	803	649
Accelerating Aon United Program expenses	132	0	251	0
Total operating expenses	3,104	2,335	5,709	4,733
Operating income	656	842	2,121	2,315
Interest income	31	5	59	10
Interest expense	(225)	(130)	(369)	(241)
Other income (expense)	236	(59)	311	(84)
Income before income taxes	698	658	2,122	2,000
Income tax expense	160	83	491	346
Net income	538	575	1,631	1,654
Less: Net income attributable to redeemable and non-redeemable noncontrolling interests	14	15	36	44
Net income attributable to Aon shareholders	$ 524	$ 560	$ 1,595	$ 1,610
Basic net income per share attributable to Aon shareholders (in dollars per share)	$ 2.47	$ 2.74	$ 7.75	$ 7.84
Diluted net income per share attributable to Aon shareholders (in dollars per share)	$ 2.46	$ 2.71	$ 7.72	$ 7.79
Weighted average ordinary shares outstanding - basic (in shares)	212.5	204.7	205.8	205.4
Weighted average ordinary shares outstanding - diluted (in shares)	213.3	206.3	206.7	206.7