v3.26.1
Fair Value Accounting - Estimated Fair Value of Financial Instruments (Detail) - USD ($)
$ in Millions
Mar. 31, 2026
Dec. 31, 2025
Mar. 31, 2025
Financial assets      
HTM $ 1,625 $ 1,584  
AFS 18,701 18,788  
Investment securities - equity 79 79  
Derivative asset 402 488 $ 253
Loans HFS 3,936 3,498  
Net loans HFI 58,681 58,216  
Mortgage servicing rights 1,516 1,494  
Financial liabilities      
Total deposits 82,723 77,159  
Other borrowings 5,610 5,240  
Derivative liabilities 36 28 $ 25
Fair Value, Nonrecurring | Carrying Amount      
Financial assets      
HTM 1,625 1,584  
Net loans HFI 58,681 58,216  
Accrued interest receivable 473 473  
Financial liabilities      
Total deposits 82,723 77,159  
Other borrowings 5,610 5,240  
Junior subordinated debt 1,072 1,076  
Accrued interest payable 120 116  
Fair Value, Nonrecurring | Estimate of Fair Value Measurement      
Financial assets      
HTM 1,450 1,427  
Net loans HFI 57,296 57,206  
Accrued interest receivable 473 473  
Financial liabilities      
Total deposits 82,749 77,185  
Other borrowings 5,610 5,242  
Junior subordinated debt 1,053 1,068  
Accrued interest payable 120 116  
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 1,450 1,427  
Net loans HFI 0 0  
Accrued interest receivable 473 473  
Financial liabilities      
Total deposits 82,749 77,185  
Other borrowings 5,610 5,242  
Junior subordinated debt 968 981  
Accrued interest payable 120 116  
Fair Value, Nonrecurring | Estimate of Fair Value Measurement | Significant Unobservable Inputs (Level 3)      
Financial assets      
HTM 0 0  
Net loans HFI 57,296 57,206  
Accrued interest receivable 0 0  
Financial liabilities      
Total deposits 0 0  
Other borrowings 0 0  
Junior subordinated debt 85 87  
Accrued interest payable 0 0  
Fair Value, Recurring      
Financial assets      
AFS 18,701 18,788  
Investment securities - equity 79 79  
Derivative asset 276 207  
Financial liabilities      
Junior subordinated debt 70 71  
Derivative liabilities 139 106  
Fair Value, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)      
Financial assets      
AFS 5,638 5,998  
Investment securities - equity 79 79  
Derivative asset 0 0  
Financial liabilities      
Junior subordinated debt 0 0  
Derivative liabilities 0 0  
Fair Value, Recurring | Significant Other Observable Inputs (Level 2)      
Financial assets      
AFS 13,063 12,790  
Investment securities - equity 0 0  
Derivative asset 227 148  
Financial liabilities      
Junior subordinated debt 0 0  
Derivative liabilities 127 105  
Fair Value, Recurring | Significant Unobservable Inputs (Level 3)      
Financial assets      
AFS 0 0  
Investment securities - equity 0 0  
Derivative asset 49 59  
Financial liabilities      
Junior subordinated debt 70 71  
Derivative liabilities 12 1  
Fair Value, Recurring | Carrying Amount      
Financial assets      
AFS 18,701 18,788  
Investment securities - equity 79 79  
Derivative asset 276 207  
Loans HFS 3,936 3,498  
Mortgage servicing rights 1,516 1,494  
Financial liabilities      
Derivative liabilities 139 106  
Fair Value, Recurring | Estimate of Fair Value Measurement      
Financial assets      
AFS 18,701 18,788  
Investment securities - equity 79 79  
Derivative asset 276 207  
Loans HFS 3,936 3,498  
Mortgage servicing rights 1,516 1,494  
Financial liabilities      
Derivative liabilities 139 106  
Fair Value, Recurring | Estimate of Fair Value Measurement | Quoted Prices in Active Markets for Identical Assets (Level 1)      
Financial assets      
AFS 5,638 5,998  
Investment securities - equity 79 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 13,063 12,790  
Investment securities - equity 0 0  
Derivative asset 227 148  
Loans HFS 2,804 2,664  
Mortgage servicing rights 0 0  
Financial liabilities      
Derivative liabilities 127 105  
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 49 59  
Loans HFS 1,132 834  
Mortgage servicing rights 1,516 1,494  
Financial liabilities      
Derivative liabilities $ 12 $ 1