Premises and Equipment - Schedule of Premises and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Leases	$ 18	$ 28
Total premises and equipment	2,317	2,394
Less: Accumulated depreciation and amortization	(1,636)	(1,641)
Premises and equipment, net	681	753
Land
Property, Plant and Equipment [Line Items]
Premises and equipment	118	126
Buildings and improvements
Property, Plant and Equipment [Line Items]
Premises and equipment	$ 680	722
Buildings and improvements | Minimum
Property, Plant and Equipment [Line Items]
Useful life (in years)	15 years
Buildings and improvements | Maximum
Property, Plant and Equipment [Line Items]
Useful life (in years)	40 years
Leasehold improvements
Property, Plant and Equipment [Line Items]
Premises and equipment	$ 616	631
Leasehold improvements | Minimum
Property, Plant and Equipment [Line Items]
Useful life (in years)	1 year
Leasehold improvements | Maximum
Property, Plant and Equipment [Line Items]
Useful life (in years)	15 years
Furniture and equipment
Property, Plant and Equipment [Line Items]
Premises and equipment	$ 814	843
Furniture and equipment | Minimum
Property, Plant and Equipment [Line Items]
Useful life (in years)	2 years
Furniture and equipment | Maximum
Property, Plant and Equipment [Line Items]
Useful life (in years)	15 years
Capitalized building leases
Property, Plant and Equipment [Line Items]
Leases	$ 19	28
Capitalized building leases | Minimum
Property, Plant and Equipment [Line Items]
Useful life (in years)	1 year
Capitalized building leases | Maximum
Property, Plant and Equipment [Line Items]
Useful life (in years)	14 years
Construction in process
Property, Plant and Equipment [Line Items]
Premises and equipment	$ 70	$ 44