Condensed Consolidated Statements of Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Revenue
Total revenue	$ 2,696	$ 2,702	$ 9,349	$ 9,113
Expenses
Compensation and benefits	1,532	1,835	4,938	5,182
Information technology	133	130	371	359
Premises	71	98	216	251
Depreciation of fixed assets	37	56	115	138
Amortization and impairment of intangible assets	34	36	87	112
Other general expense	299	1,348	965	1,955
Total operating expenses	2,106	3,503	6,692	7,997
Operating income (loss)	590	(801)	2,657	1,116
Interest income	7	3	15	9
Interest expense	(103)	(80)	(296)	(237)
Other income (expense)	16	10	71	7
Income (loss) before income taxes	510	(868)	2,447	895
Income tax expense	92	23	467	460
Net income (loss)	418	(891)	1,980	435
Less: Net income attributable to noncontrolling interests	10	9	48	43
Net income (loss) attributable to Aon shareholders	$ 408	$ (900)	$ 1,932	$ 392
Basic net income (loss) per share attributable to Aon shareholders (in dollars per share)	$ 1.93	$ (3.99)	$ 9.06	$ 1.73
Diluted net income (loss) per share attributable to Aon shareholders (in dollars per share)	$ 1.92	$ (3.99)	$ 9.00	$ 1.72
Weighted average ordinary shares outstanding - basic (in shares)	210.9	225.4	213.2	226.5
Weighted average ordinary shares outstanding - diluted (in shares)	212.6	225.4	214.6	227.7