v3.22.0.1
Other Assets - Other Assets (Parenthetical) (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
Schedule Of Other Assets [Line Items]      
Accumulated depreciation and amortization $ 10,810 $ 10,120  
Property, leasehold improvements and equipment used for operation 6,710 6,540  
Foreclosed real estate included in property, leasehold improvements and equipment $ 194 $ 318  
Amortization period - Capitalized costs of software developed or obtained for internal use 3 years 3 years  
Operating lease right-of-use assets $ 2,292 $ 2,280  
Investments in qualified affordable housing projects 714 678  
Property Leasehold Improvements And Equipment [Member]      
Schedule Of Other Assets [Line Items]      
Impairment of property leasehold improvements and equipment 143 171 $ 0
Asset Management [Member]      
Schedule Of Other Assets [Line Items]      
Assets classified as held for sale 1,020 437  
Operating lease right-of-use assets [Member]      
Schedule Of Other Assets [Line Items]      
Operating lease right-of-use assets $ 305 $ 182 $ 963