Condensed Consolidated Statements of Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Revenue
Total revenue	$ 2,983	$ 2,886	$ 6,653	$ 6,411
Expenses
Compensation and benefits	1,639	1,628	3,406	3,347
Information technology	115	115	238	229
Premises	73	76	145	153
Depreciation of fixed assets	40	41	78	82
Amortization and impairment of intangible assets	25	36	53	76
Other general expense	391	318	666	607
Total operating expenses	2,283	2,214	4,586	4,494
Operating income	700	672	2,067	1,917
Interest income	5	3	8	6
Interest expense	(102)	(78)	(193)	(157)
Other income (expense)	30	(1)	55	(3)
Income before income taxes	633	596	1,937	1,763
Income tax expense	119	203	375	437
Net income	514	393	1,562	1,326
Less: Net income attributable to noncontrolling interests	13	14	38	34
Net income attributable to Aon shareholders	$ 501	$ 379	$ 1,524	$ 1,292
Basic net income per share attributable to Aon shareholders (in dollars per share)	$ 2.35	$ 1.67	$ 7.11	$ 5.69
Diluted net income per share attributable to Aon shareholders (in dollars per share)	$ 2.33	$ 1.66	$ 7.07	$ 5.66
Weighted average ordinary shares outstanding - basic (in shares)	213.3	227.0	214.3	227.0
Weighted average ordinary shares outstanding - diluted (in shares)	214.7	228.0	215.6	228.1