Condensed Consolidated Statements of Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Revenue
Total revenue	$ 3,177	$ 2,983	$ 7,048	$ 6,653
Expenses
Compensation and benefits	1,754	1,639	3,546	3,406
Information technology	129	115	268	238
Premises	68	73	143	145
Depreciation of fixed assets	39	40	77	78
Amortization and impairment of intangible assets	25	25	50	53
Other general expense	320	391	649	666
Total operating expenses	2,335	2,283	4,733	4,586
Operating income	842	700	2,315	2,067
Interest income	5	5	10	8
Interest expense	(130)	(102)	(241)	(193)
Other income (expense)	(59)	30	(84)	55
Income before income taxes	658	633	2,000	1,937
Income tax expense	83	119	346	375
Net income	575	514	1,654	1,562
Less: Net income attributable to noncontrolling interests	15	13	44	38
Net income attributable to Aon shareholders	$ 560	$ 501	$ 1,610	$ 1,524
Basic net income per share attributable to Aon shareholders (in dollars per share)	$ 2.74	$ 2.35	$ 7.84	$ 7.11
Diluted net income per share attributable to Aon shareholders (in dollars per share)	$ 2.71	$ 2.33	$ 7.79	$ 7.07
Weighted average ordinary shares outstanding - basic (in shares)	204.7	213.3	205.4	214.3
Weighted average ordinary shares outstanding - diluted (in shares)	206.3	214.7	206.7	215.6