v3.26.1
Fair Value Accounting - Estimated Fair Value of Financial Instruments (Detail) - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Jun. 30, 2025
Financial assets      
HTM $ 1,676 $ 1,584  
AFS 18,880 18,788  
Investment securities - equity 80 79  
Derivative asset 512 488 $ 389
Loans HFS 4,347 3,498  
Net loans HFI 60,462 58,216  
Mortgage servicing rights 1,500 1,494  
Financial liabilities      
Total deposits 81,874 77,159  
Other borrowings 6,236 5,240  
Derivative liabilities 40 28 28
Margin, liability 0 7 $ (41)
Fair Value, Nonrecurring | Carrying Amount      
Financial assets      
HTM 1,676 1,584  
Net loans HFI 60,462 58,216  
Accrued interest receivable 505 473  
Financial liabilities      
Total deposits 81,874 77,159  
Other borrowings 6,236 5,240  
Junior subordinated debt 1,069 1,076  
Accrued interest payable 109 116  
Fair Value, Nonrecurring | Estimate of Fair Value Measurement      
Financial assets      
HTM 1,497 1,427  
Net loans HFI 58,938 57,206  
Accrued interest receivable 505 473  
Financial liabilities      
Total deposits 81,899 77,185  
Other borrowings 6,239 5,242  
Junior subordinated debt 1,066 1,068  
Accrued interest payable 109 116  
Fair Value, Nonrecurring | Estimate of Fair Value Measurement | Quoted Prices in Active Markets for Identical Assets (Level 1)      
Financial assets      
HTM 0 0  
Net loans HFI 0 0  
Accrued interest receivable 0 0  
Financial liabilities      
Total deposits 0 0  
Other borrowings 0 0  
Junior subordinated debt 0 0  
Accrued interest payable 0 0  
Fair Value, Nonrecurring | Estimate of Fair Value Measurement | Significant Other Observable Inputs (Level 2)      
Financial assets      
HTM 1,497 1,427  
Net loans HFI 0 0  
Accrued interest receivable 505 473  
Financial liabilities      
Total deposits 81,899 77,185  
Other borrowings 6,239 5,242  
Junior subordinated debt 980 981  
Accrued interest payable 109 116  
Fair Value, Nonrecurring | Estimate of Fair Value Measurement | Significant Unobservable Inputs (Level 3)      
Financial assets      
HTM 0 0  
Net loans HFI 58,938 57,206  
Accrued interest receivable 0 0  
Financial liabilities      
Total deposits 0 0  
Other borrowings 0 0  
Junior subordinated debt 86 87  
Accrued interest payable 0 0  
Fair Value, Recurring      
Financial assets      
AFS 18,880 18,788  
Investment securities - equity 80 79  
Derivative asset 165 207  
Financial liabilities      
Junior subordinated debt 71 71  
Derivative liabilities 104 106  
Fair Value, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)      
Financial assets      
AFS 5,523 5,998  
Investment securities - equity 80 79  
Derivative asset 0 0  
Financial liabilities      
Junior subordinated debt 0 0  
Derivative liabilities 0 0  
Margin, asset 411 366  
Margin, liability 0 7  
Fair Value, Recurring | Significant Other Observable Inputs (Level 2)      
Financial assets      
AFS 13,357 12,790  
Investment securities - equity 0 0  
Derivative asset 106 148  
Financial liabilities      
Junior subordinated debt 0 0  
Derivative liabilities 103 105  
Fair Value, Recurring | Significant Unobservable Inputs (Level 3)      
Financial assets      
AFS 0 0  
Investment securities - equity 0 0  
Derivative asset 59 59  
Financial liabilities      
Junior subordinated debt 71 71  
Derivative liabilities 1 1  
Fair Value, Recurring | Carrying Amount      
Financial assets      
AFS 18,880 18,788  
Investment securities - equity 80 79  
Derivative asset 165 207  
Loans HFS 4,347 3,498  
Mortgage servicing rights 1,500 1,494  
Financial liabilities      
Derivative liabilities 104 106  
Fair Value, Recurring | Estimate of Fair Value Measurement      
Financial assets      
AFS 18,880 18,788  
Investment securities - equity 80 79  
Derivative asset 165 207  
Loans HFS 4,347 3,498  
Mortgage servicing rights 1,500 1,494  
Financial liabilities      
Derivative liabilities 104 106  
Fair Value, Recurring | Estimate of Fair Value Measurement | Quoted Prices in Active Markets for Identical Assets (Level 1)      
Financial assets      
AFS 5,523 5,998  
Investment securities - equity 80 79  
Derivative asset 0 0  
Loans HFS 0 0  
Mortgage servicing rights 0 0  
Financial liabilities      
Derivative liabilities 0 0  
Fair Value, Recurring | Estimate of Fair Value Measurement | Significant Other Observable Inputs (Level 2)      
Financial assets      
AFS 13,357 12,790  
Investment securities - equity 0 0  
Derivative asset 106 148  
Loans HFS 3,285 2,664  
Mortgage servicing rights 0 0  
Financial liabilities      
Derivative liabilities 103 105  
Fair Value, Recurring | Estimate of Fair Value Measurement | Significant Unobservable Inputs (Level 3)      
Financial assets      
AFS 0 0  
Investment securities - equity 0 0  
Derivative asset 59 59  
Loans HFS 1,062 834  
Mortgage servicing rights 1,500 1,494  
Financial liabilities      
Derivative liabilities $ 1 $ 1