v3.26.1
Fair Value Accounting - Fair Value of Assets and Liabilities (Detail) - USD ($)
$ in Millions
Jun. 30, 2026
Mar. 31, 2026
Dec. 31, 2025
Jun. 30, 2025
Mar. 31, 2025
Dec. 31, 2024
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS $ 18,880   $ 18,788      
Investment securities - equity 80   79      
Fair value of mortgage servicing rights 1,500 $ 1,516 1,494 $ 1,044 $ 1,241 $ 1,127
Derivative asset 512   488 389    
Derivative liabilities 40   28 28    
Margin, liability 0   7 $ (41)    
CLO            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 3,221   2,747      
Commercial MBS issued by GSEs and GNMA            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 514   635      
Corporate debt securities            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 222   297      
Private label residential MBS            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 1,136   1,039      
Residential MBS issued by GSEs and GNMA            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 7,428   7,230      
Tax-exempt            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 794   802      
U.S. Treasury securities            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 5,494   5,970      
Other            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 71   68      
CRA investments            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Investment securities - equity 28   27      
Preferred Stock            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Investment securities - equity 52   52      
Loans HFI            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Cumulative basis adjustment, including carrying value of hedged items increase (decrease) (42)   0      
Fair Value, Recurring            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 18,880   18,788      
Investment securities - equity 80   79      
Loans HFS 4,224   3,364      
Fair value of mortgage servicing rights 1,500   1,494      
Derivative asset 165   207      
Junior subordinated debt 71   71      
Derivative liabilities 104   106      
Fair Value, Recurring | CLO            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 3,221   2,747      
Fair Value, Recurring | Commercial MBS issued by GSEs and GNMA            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 514   635      
Fair Value, Recurring | Corporate debt securities            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 222   297      
Fair Value, Recurring | Private label residential MBS            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 1,136   1,039      
Fair Value, Recurring | Residential MBS issued by GSEs and GNMA            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 7,428   7,230      
Fair Value, Recurring | Tax-exempt            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 794   802      
Fair Value, Recurring | U.S. Treasury securities            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 5,494   5,970      
Fair Value, Recurring | Other            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 71   68      
Fair Value, Recurring | CRA investments            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Investment securities - equity 28   27      
Fair Value, Recurring | Preferred Stock            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Investment securities - equity 52   52      
Fair Value, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 5,523   5,998      
Investment securities - equity 80   79      
Loans HFS 0   0      
Fair value of mortgage servicing rights 0   0      
Derivative asset 0   0      
Junior subordinated debt 0   0      
Derivative liabilities 0   0      
Margin, asset 411   366      
Margin, liability 0   7      
Fair Value, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | CLO            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 0   0      
Fair Value, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Commercial MBS issued by GSEs and GNMA            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 0   0      
Fair Value, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Corporate debt securities            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 0   0      
Fair Value, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Private label residential MBS            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 0   0      
Fair Value, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Residential MBS issued by GSEs and GNMA            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 0   0      
Fair Value, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Tax-exempt            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 0   0      
Fair Value, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. Treasury securities            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 5,494   5,970      
Fair Value, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 29   28      
Fair Value, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | CRA investments            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Investment securities - equity 28   27      
Fair Value, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Preferred Stock            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Investment securities - equity 52   52      
Fair Value, Recurring | Significant Other Observable Inputs (Level 2)            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 13,357   12,790      
Investment securities - equity 0   0      
Loans HFS 3,261   2,664      
Fair value of mortgage servicing rights 0   0      
Derivative asset 106   148      
Junior subordinated debt 0   0      
Derivative liabilities 103   105      
Fair Value, Recurring | Significant Other Observable Inputs (Level 2) | CLO            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 3,221   2,747      
Fair Value, Recurring | Significant Other Observable Inputs (Level 2) | Commercial MBS issued by GSEs and GNMA            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 514   635      
Fair Value, Recurring | Significant Other Observable Inputs (Level 2) | Corporate debt securities            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 222   297      
Fair Value, Recurring | Significant Other Observable Inputs (Level 2) | Private label residential MBS            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 1,136   1,039      
Fair Value, Recurring | Significant Other Observable Inputs (Level 2) | Residential MBS issued by GSEs and GNMA            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 7,428   7,230      
Fair Value, Recurring | Significant Other Observable Inputs (Level 2) | Tax-exempt            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 794   802      
Fair Value, Recurring | Significant Other Observable Inputs (Level 2) | U.S. Treasury securities            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 0   0      
Fair Value, Recurring | Significant Other Observable Inputs (Level 2) | Other            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 42   40      
Fair Value, Recurring | Significant Other Observable Inputs (Level 2) | CRA investments            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Investment securities - equity 0   0      
Fair Value, Recurring | Significant Other Observable Inputs (Level 2) | Preferred Stock            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Investment securities - equity 0   0      
Fair Value, Recurring | Significant Unobservable Inputs (Level 3)            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 0   0      
Investment securities - equity 0   0      
Loans HFS 963   700      
Fair value of mortgage servicing rights 1,500   1,494      
Derivative asset 59   59      
Junior subordinated debt 71   71      
Derivative liabilities 1   1      
Fair Value, Recurring | Significant Unobservable Inputs (Level 3) | CLO            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 0   0      
Fair Value, Recurring | Significant Unobservable Inputs (Level 3) | Commercial MBS issued by GSEs and GNMA            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 0   0      
Fair Value, Recurring | Significant Unobservable Inputs (Level 3) | Corporate debt securities            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 0   0      
Fair Value, Recurring | Significant Unobservable Inputs (Level 3) | Private label residential MBS            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 0   0      
Fair Value, Recurring | Significant Unobservable Inputs (Level 3) | Residential MBS issued by GSEs and GNMA            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 0   0      
Fair Value, Recurring | Significant Unobservable Inputs (Level 3) | Tax-exempt            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 0   0      
Fair Value, Recurring | Significant Unobservable Inputs (Level 3) | U.S. Treasury securities            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 0   0      
Fair Value, Recurring | Significant Unobservable Inputs (Level 3) | Other            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
AFS 0   0      
Fair Value, Recurring | Significant Unobservable Inputs (Level 3) | CRA investments            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Investment securities - equity 0   0      
Fair Value, Recurring | Significant Unobservable Inputs (Level 3) | Preferred Stock            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Investment securities - equity $ 0   $ 0