Loans - Summary of Estimated Fair Value of Loans and Lending Commitments that are not Accounted for at Fair Value (Detail) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Schedule Of Estimated Fair Value Of Loans And Lending Commitments That Are Not Accounted For At Fair Value [Line Items]
Loans	$ 179,286	$ 158,562
Amortized Cost
Schedule Of Estimated Fair Value Of Loans And Lending Commitments That Are Not Accounted For At Fair Value [Line Items]
Loans	167,037	139,934
Loans, Estimated Fair Value, Level 3	169,042	141,803
Amortized Cost | Level 2
Schedule Of Estimated Fair Value Of Loans And Lending Commitments That Are Not Accounted For At Fair Value [Line Items]
Loans, Estimated Fair Value, Level 1	85,921	87,676
Amortized Cost | Level 3
Schedule Of Estimated Fair Value Of Loans And Lending Commitments That Are Not Accounted For At Fair Value [Line Items]
Loans, Estimated Fair Value, Level 2	83,121	54,127
Held For Sale
Schedule Of Estimated Fair Value Of Loans And Lending Commitments That Are Not Accounted For At Fair Value [Line Items]
Loans	4,594	7,859
Loans held for sale	4,594	7,859
Loans held for sale, Estimated Fair Value, Level 3	4,606	7,887
Held For Sale | Level 2
Schedule Of Estimated Fair Value Of Loans And Lending Commitments That Are Not Accounted For At Fair Value [Line Items]
Loans held for sale, Estimated Fair Value, Level 1	2,592	5,970
Held For Sale | Level 3
Schedule Of Estimated Fair Value Of Loans And Lending Commitments That Are Not Accounted For At Fair Value [Line Items]
Loans held for sale, Estimated Fair Value, Level 2	$ 2,014	$ 1,917