Goodwill and Other Intangible Assets - Gross Carrying Amount, Accumulated Amortization and Net Carrying Amount of Other Intangible Assets (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 3,938	$ 3,897
Accumulated Amortization	(2,618)	(2,353)
Net Carrying Amount	1,320	1,544	$ 1,816
Client relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	2,761	2,728
Accumulated Amortization	(1,808)	(1,626)
Net Carrying Amount	953	1,102
Technology
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	402	402
Accumulated Amortization	(216)	(178)
Net Carrying Amount	186	224
Core deposits
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	690	683
Accumulated Amortization	(516)	(477)
Net Carrying Amount	174	206
Other
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	85	84
Accumulated Amortization	(78)	(72)
Net Carrying Amount	$ 7	$ 12