v3.26.1
Loans - Summary of Estimated Fair Value of Loans and Lending Commitments that are not Accounted for at Fair Value (Detail) - USD ($)
$ in Millions
Mar. 31, 2026
Dec. 31, 2025
Schedule Of Estimated Fair Value Of Loans And Lending Commitments That Are Not Accounted For At Fair Value [Line Items]    
Loans $ 252,849 $ 237,734
Loans held for sale 23,112 22,066
Reported Value Measurement    
Schedule Of Estimated Fair Value Of Loans And Lending Commitments That Are Not Accounted For At Fair Value [Line Items]    
Loans held for sale 23,112 22,066
Level 2 | Estimate of Fair Value Measurement    
Schedule Of Estimated Fair Value Of Loans And Lending Commitments That Are Not Accounted For At Fair Value [Line Items]    
Loans held for sale 21,593 21,383
Level 3 | Estimate of Fair Value Measurement    
Schedule Of Estimated Fair Value Of Loans And Lending Commitments That Are Not Accounted For At Fair Value [Line Items]    
Loans held for sale 1,835 694
Total | Estimate of Fair Value Measurement    
Schedule Of Estimated Fair Value Of Loans And Lending Commitments That Are Not Accounted For At Fair Value [Line Items]    
Loans held for sale 23,428 22,077
Amortized Cost    
Schedule Of Estimated Fair Value Of Loans And Lending Commitments That Are Not Accounted For At Fair Value [Line Items]    
Loans 225,358 210,763
Amortized Cost | Reported Value Measurement    
Schedule Of Estimated Fair Value Of Loans And Lending Commitments That Are Not Accounted For At Fair Value [Line Items]    
Loans 225,358 210,763
Amortized Cost | Level 2 | Estimate of Fair Value Measurement    
Schedule Of Estimated Fair Value Of Loans And Lending Commitments That Are Not Accounted For At Fair Value [Line Items]    
Loans 119,478 113,861
Amortized Cost | Level 3 | Estimate of Fair Value Measurement    
Schedule Of Estimated Fair Value Of Loans And Lending Commitments That Are Not Accounted For At Fair Value [Line Items]    
Loans 106,137 97,210
Amortized Cost | Total | Estimate of Fair Value Measurement    
Schedule Of Estimated Fair Value Of Loans And Lending Commitments That Are Not Accounted For At Fair Value [Line Items]    
Loans 225,615 211,071
Held For Sale    
Schedule Of Estimated Fair Value Of Loans And Lending Commitments That Are Not Accounted For At Fair Value [Line Items]    
Loans 23,112 22,066
Loans held for sale $ 23,112 $ 22,066