Goodwill and Other Intangible Assets - Summary of Intangible Assets and Accumulated Amortization Included in the Consolidated Statements of Condition (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Intangible Assets [Line Items]
Gross Carrying Amount	$ 444	$ 449
Accumulated Amortization	(172)	(151)
Net Carrying Value	272	298
Core deposit intangibles
Intangible Assets [Line Items]
Gross Carrying Amount	371	371
Accumulated Amortization	(150)	(128)
Net Carrying Value	221	243
Client relationships
Intangible Assets [Line Items]
Gross Carrying Amount	37	37
Accumulated Amortization	(13)	(11)
Net Carrying Value	24	26
Other
Intangible Assets [Line Items]
Gross Carrying Amount	36	41
Accumulated Amortization	(9)	(12)
Net Carrying Value	$ 27	$ 29