Consolidated Statements of Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Income Statement [Abstract]
Revenue	$ 5,549	$ 5,083
Expense:
Compensation and benefits	3,100	2,807
Other operating expenses	1,004	918
Operating expenses	4,104	3,725
Operating income	1,445	1,358
Other net benefit credits	62	71
Interest income	1	0
Interest expense	(110)	(118)
Investment income	26	11
Income before income taxes	1,424	1,322
Income tax expense	338	324
Net income before non-controlling interests	1,086	998
Less: Net income attributable to non-controlling interests	15	15
Net income attributable to the Company	$ 1,071	$ 983
Net income per share attributable to the Company:
Basic (usd per share)	$ 2.13	$ 1.93
Diluted (usd per share)	$ 2.10	$ 1.91
Average number of shares outstanding:
Basic (in shares)	503	509
Diluted (in shares)	509	514
Shares outstanding (in shares)	502	509