Condensed Consolidated Statements of Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Revenue
Total revenue	$ 3,721	$ 2,953	$ 11,551	$ 10,001
Expenses
Compensation and benefits	2,150	1,685	6,163	5,231
Information technology	141	135	397	403
Premises	88	74	241	217
Depreciation of fixed assets	47	42	136	119
Amortization and impairment of intangible assets	174	20	318	70
Other general expense	429	300	1,232	949
Accelerating Aon United Program expenses	69	6	320	6
Total operating expenses	3,098	2,262	8,807	6,995
Operating income	623	691	2,744	3,006
Interest income	4	9	63	19
Interest expense	(213)	(119)	(582)	(360)
Other income (expense)	35	(21)	346	(105)
Income before income taxes	449	560	2,571	2,560
Income tax expense	94	93	585	439
Net income	355	467	1,986	2,121
Less: Net income attributable to redeemable and non-redeemable noncontrolling interests	12	11	48	55
Net income attributable to Aon shareholders	$ 343	$ 456	$ 1,938	$ 2,066
Basic net income per share attributable to Aon shareholders (in dollars per share)	$ 1.58	$ 2.25	$ 9.24	$ 10.10
Diluted net income per share attributable to Aon shareholders (in dollars per share)	$ 1.57	$ 2.23	$ 9.20	$ 10.03
Weighted average ordinary shares outstanding - basic (in shares)	217.4	202.9	209.7	204.6
Weighted average ordinary shares outstanding - diluted (in shares)	218.4	204.6	210.6	206.0