Consolidated Statements of Income - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Revenue
Total revenue	$ 15,698	$ 13,376	$ 12,479
Expenses
Compensation and benefits	8,283	6,902	6,477
Information technology	539	534	509
Premises	325	294	289
Depreciation of fixed assets	183	167	151
Amortization and impairment of intangible assets	503	89	113
Other general expense	1,641	1,470	1,271
Accelerating Aon United Program expenses	389	135	0
Total operating expenses	11,863	9,591	8,810
Operating income	3,835	3,785	3,669
Interest income	67	31	18
Interest expense	(788)	(484)	(406)
Other income (expense)	348	(163)	(125)
Income before income taxes	3,462	3,169	3,156
Income tax expense	742	541	510
Net income	2,720	2,628	2,646
Less: Net income attributable to redeemable and nonredeemable noncontrolling interests	66	64	57
Net income attributable to Aon shareholders	$ 2,654	$ 2,564	$ 2,589
Basic net income per share attributable to Aon shareholders (in dollars per share)	$ 12.55	$ 12.60	$ 12.23
Diluted net income per share attributable to Aon shareholders (in dollars per share)	$ 12.49	$ 12.51	$ 12.14
Weighted average ordinary shares outstanding - basic (in shares)	211.4	203.5	211.7
Weighted average ordinary shares outstanding - diluted (in shares)	212.5	205.0	213.2