v3.22.0.1
Loans - Summary of estimated fair value of loans and lending commitments (Detail) - USD ($)
$ in Millions
Dec. 31, 2021
Dec. 31, 2020
Schedule Of Estimated Fair Value Of Loans And Lending Commitments That Are Not Accounted For At Fair Value [Line Items]    
Loans, Carrying Value $ 158,562 $ 116,115
Amortized cost [Member]    
Schedule Of Estimated Fair Value Of Loans And Lending Commitments That Are Not Accounted For At Fair Value [Line Items]    
Loans, Carrying Value 139,934 99,691
Loans, Estimated Fair Value 141,803 101,305
Amortized cost [Member] | Level 2 [Member]    
Schedule Of Estimated Fair Value Of Loans And Lending Commitments That Are Not Accounted For At Fair Value [Line Items]    
Loans, Estimated Fair Value 87,676 52,793
Amortized cost [Member] | Level 3 [Member]    
Schedule Of Estimated Fair Value Of Loans And Lending Commitments That Are Not Accounted For At Fair Value [Line Items]    
Loans, Estimated Fair Value 54,127 48,512
Held for sale [Member]    
Schedule Of Estimated Fair Value Of Loans And Lending Commitments That Are Not Accounted For At Fair Value [Line Items]    
Loans, Carrying Value 7,859 2,799
Loans Receivable Held-for-sale, Amount 7,859 2,799
Loans, Estimated Fair Value 7,887 2,812
Held for sale [Member] | Level 2 [Member]    
Schedule Of Estimated Fair Value Of Loans And Lending Commitments That Are Not Accounted For At Fair Value [Line Items]    
Loans, Estimated Fair Value 5,970 1,541
Held for sale [Member] | Level 3 [Member]    
Schedule Of Estimated Fair Value Of Loans And Lending Commitments That Are Not Accounted For At Fair Value [Line Items]    
Loans, Estimated Fair Value $ 1,917 $ 1,271