Consolidated Statements of Income - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Revenue
Total revenue	$ 12,479	$ 12,193	$ 11,066
Expenses
Compensation and benefits	6,477	6,738	5,905
Information technology	509	477	444
Premises	289	327	291
Depreciation of fixed assets	151	179	167
Amortization and impairment of intangible assets	113	147	246
Other general expense	1,271	2,235	1,232
Total operating expenses	8,810	10,103	8,285
Operating income	3,669	2,090	2,781
Interest income	18	11	6
Interest expense	(406)	(322)	(334)
Other income (expense)	(125)	152	13
Income before income taxes	3,156	1,931	2,466
Income tax expense	510	623	448
Net income	2,646	1,308	2,018
Less: Net income attributable to noncontrolling interests	57	53	49
Net income attributable to Aon shareholders	$ 2,589	$ 1,255	$ 1,969
Basic net income per share attributable to Aon shareholders (in dollars per share)	$ 12.23	$ 5.59	$ 8.49
Diluted net income per share attributable to Aon shareholders (in dollars per share)	$ 12.14	$ 5.55	$ 8.45
Weighted average ordinary shares outstanding - basic (in shares)	211.7	224.7	231.9
Weighted average ordinary shares outstanding - diluted (in shares)	213.2	226.1	233.1