Bank Premises and Equipment - Summary of Bank Premises and Equipment (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Property, Plant and Equipment [Line Items]
Accumulated depreciation and amortization	$ (3,674)	$ (3,473)
Total bank premises and equipment	2,475	2,349
Equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 2,769	2,578
Equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Life	1 year
Equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Life	20 years
Buildings
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 1,784	1,742
Buildings | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Life	1 year
Buildings | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Life	30 years
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 760	685
Leasehold improvements | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Life	1 year
Leasehold improvements | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Life	30 years
Land and and improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 623	618
Construction in progress
Property, Plant and Equipment [Line Items]
Property and equipment, gross	199	180
Land and improvements held for sale
Property, Plant and Equipment [Line Items]
Property and equipment, gross	10	15
Buildings held for sale
Property, Plant and Equipment [Line Items]
Property and equipment, gross	4	4
Other property
Property, Plant and Equipment [Line Items]
Land improvements	$ 1	$ 9