Goodwill and Other Intangible Assets - Gross Carrying Amount, Accumulated Amortization and Net Carrying Amount of Other Intangible Assets (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 3,954	$ 3,981
Accumulated Amortization	(2,210)	(2,165)
Net Carrying Amount	1,744	1,816	$ 1,827
Client relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	2,766	2,786
Accumulated Amortization	(1,526)	(1,497)
Net Carrying Amount	1,240	1,289
Technology
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	403	403
Accumulated Amortization	(151)	(142)
Net Carrying Amount	252	261
Core deposits
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	691	696
Accumulated Amortization	(456)	(451)
Net Carrying Amount	235	245
Other
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	94	96
Accumulated Amortization	(77)	(75)
Net Carrying Amount	$ 17	$ 21