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Loans and Leases and the Allowance for Credit Losses - Loan and Leases Considered Nonaccrual and Interest Income Recognized on Loans (Detail) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended |  |  |  |
--- | --- | --- | --- | --- | --- | ---
Sep. 30, 2024 | Sep. 30, 2023 | Sep. 30, 2024 | Sep. 30, 2023 | Jun. 30, 2024 | Jan. 01, 2024 | Jun. 30, 2023 | Jan. 01, 2023
Financing Receivable, Impaired [Line Items] |  |  |  |  |  |  |  |
Amortized Cost with Allowance | $ 1,235 | $ 1,038 | $ 1,235 | $ 1,038 |  |  |  |
Amortized Cost without Allowance | 691 | 1,304 | 691 | 1,304 |  |  |  |
Total | 1,926 | 2,342 | 1,926 | 2,342 |  |  |  |
Amortized Cost |  |  |  |  | $ 2,024 | $ 2,166 | $ 2,436 | $ 2,439
Interest Income Recognized | 17 | 22 | 64 | 52 |  |  |  |
Commercial and industrial |  |  |  |  |  |  |  |
Financing Receivable, Impaired [Line Items] |  |  |  |  |  |  |  |
Amortized Cost with Allowance | 610 | 366 | 610 | 366 |  |  |  |
Amortized Cost without Allowance | 200 | 300 | 200 | 300 |  |  |  |
Total | 810 | 666 | 810 | 666 |  |  |  |
Amortized Cost |  |  |  |  | 805 | 670 | 607 | 504
Interest Income Recognized | 5 | 7 | 14 | 13 |  |  |  |
Commercial Real Estate | Commercial |  |  |  |  |  |  |  |
Financing Receivable, Impaired [Line Items] |  |  |  |  |  |  |  |
Amortized Cost with Allowance | 348 | 417 | 348 | 417 |  |  |  |
Amortized Cost without Allowance | 230 | 638 | 230 | 638 |  |  |  |
Total | 578 | 1,055 | 578 | 1,055 |  |  |  |
Amortized Cost |  |  |  |  | 707 | 869 | 1,192 | 1,240
Interest Income Recognized | 5 | 9 | 31 | 18 |  |  |  |
Commercial Real Estate | Residential builder and developer |  |  |  |  |  |  |  |
Financing Receivable, Impaired [Line Items] |  |  |  |  |  |  |  |
Amortized Cost with Allowance | 2 | 3 | 2 | 3 |  |  |  |
Amortized Cost without Allowance | 0 | 0 | 0 | 0 |  |  |  |
Total | 2 | 3 | 2 | 3 |  |  |  |
Amortized Cost |  |  |  |  | 2 | 3 | 1 | 1
Interest Income Recognized | 1 | 0 | 1 | 0 |  |  |  |
Commercial Real Estate | Other commercial construction |  |  |  |  |  |  |  |
Financing Receivable, Impaired [Line Items] |  |  |  |  |  |  |  |
Amortized Cost with Allowance | 21 | 4 | 21 | 4 |  |  |  |
Amortized Cost without Allowance | 63 | 132 | 63 | 132 |  |  |  |
Total | 84 | 136 | 84 | 136 |  |  |  |
Amortized Cost |  |  |  |  | 77 | 171 | 146 | 125
Interest Income Recognized | 0 | 0 | 3 | 2 |  |  |  |
Residential Real Estate | Residential |  |  |  |  |  |  |  |
Financing Receivable, Impaired [Line Items] |  |  |  |  |  |  |  |
Amortized Cost with Allowance | 113 | 91 | 113 | 91 |  |  |  |
Amortized Cost without Allowance | 106 | 150 | 106 | 150 |  |  |  |
Total | 219 | 241 | 219 | 241 |  |  |  |
Amortized Cost |  |  |  |  | 205 | 215 | 239 | 272
Interest Income Recognized | 4 | 3 | 10 | 12 |  |  |  |
Residential Real Estate | Residential — limited documentation |  |  |  |  |  |  |  |
Financing Receivable, Impaired [Line Items] |  |  |  |  |  |  |  |
Amortized Cost with Allowance | 22 | 22 | 22 | 22 |  |  |  |
Amortized Cost without Allowance | 35 | 40 | 35 | 40 |  |  |  |
Total | 57 | 62 | 57 | 62 |  |  |  |
Amortized Cost |  |  |  |  | 55 | 55 | 67 | 78
Interest Income Recognized | 0 | 1 | 1 | 1 |  |  |  |
Consumer: | Home equity lines and loans |  |  |  |  |  |  |  |
Financing Receivable, Impaired [Line Items] |  |  |  |  |  |  |  |
Amortized Cost with Allowance | 39 | 48 | 39 | 48 |  |  |  |
Amortized Cost without Allowance | 43 | 30 | 43 | 30 |  |  |  |
Total | 82 | 78 | 82 | 78 |  |  |  |
Amortized Cost |  |  |  |  | 79 | 81 | 77 | 85
Interest Income Recognized | 2 | 2 | 4 | 6 |  |  |  |
Consumer: | Recreational finance |  |  |  |  |  |  |  |
Financing Receivable, Impaired [Line Items] |  |  |  |  |  |  |  |
Amortized Cost with Allowance | 17 | 21 | 17 | 21 |  |  |  |
Amortized Cost without Allowance | 11 | 10 | 11 | 10 |  |  |  |
Total | 28 | 31 | 28 | 31 |  |  |  |
Amortized Cost |  |  |  |  | 25 | 36 | 32 | 45
Interest Income Recognized | 0 | 0 | 0 | 0 |  |  |  |
Consumer: | Automobile |  |  |  |  |  |  |  |
Financing Receivable, Impaired [Line Items] |  |  |  |  |  |  |  |
Amortized Cost with Allowance | 8 | 12 | 8 | 12 |  |  |  |
Amortized Cost without Allowance | 3 | 4 | 3 | 4 |  |  |  |
Total | 11 | 16 | 11 | 16 |  |  |  |
Amortized Cost |  |  |  |  | 11 | 14 | 22 | 40
Interest Income Recognized | 0 | 0 | 0 | 0 |  |  |  |
Consumer: | Other |  |  |  |  |  |  |  |
Financing Receivable, Impaired [Line Items] |  |  |  |  |  |  |  |
Amortized Cost with Allowance | 55 | 54 | 55 | 54 |  |  |  |
Amortized Cost without Allowance | 0 | 0 | 0 | 0 |  |  |  |
Total | 55 | 54 | 55 | 54 |  |  |  |
Amortized Cost |  |  |  |  | $ 58 | $ 52 | $ 53 | $ 49
Interest Income Recognized | $ 0 | $ 0 | $ 0 | $ 0 |  |  |  |

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