Goodwill and Intangible Assets - Net Amortizable Intangible Assets Rollforward (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Mar. 01, 2021
Finite-lived Intangible Assets [Roll Forward]
Beginning balance	$ 4,980	$ 2,107
Acquired	3,978	3,323
Disposals	(36)	(79)
Amortization expense	(612)	(373)
Other	50	2
Ending balance	8,360	4,980
IS
Finite-lived Intangible Assets [Roll Forward]
Beginning balance	127	227
Acquired	0	14
Disposals	0	(79)
Amortization expense	(23)	(35)
Other	0	0
Ending balance	104	127
WM
Finite-lived Intangible Assets [Roll Forward]
Beginning balance	4,809	1,828
Acquired	134	3,309
Disposals	(36)	0
Amortization expense	(495)	(330)
Other	51	2
Ending balance	4,463	4,809
IM
Finite-lived Intangible Assets [Roll Forward]
Beginning balance	44	52
Acquired	3,844	0
Disposals	0	0
Amortization expense	(94)	(8)
Other	(1)	0
Ending balance	$ 3,793	$ 44
WM and IM | Eaton Vance Corp.
Finite-lived Intangible Assets [Roll Forward]
Non-amortizable acquired intangible assets			$ 2,100