Goodwill and Other Intangible Assets - Gross Carrying Amount and Accumulated Amortization of Intangible Assets (Details) - USD ($) $ in Millions |
Dec. 31, 2025 |
Dec. 31, 2024 |
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| Goodwill [Line Items] | ||
| Gross Carrying Amount | $ 526 | $ 526 |
| Accumulated Amortization | 518 | 499 |
| Core deposit intangibles | ||
| Goodwill [Line Items] | ||
| Gross Carrying Amount | 356 | 356 |
| Accumulated Amortization | 352 | 342 |
| PCCR intangibles | ||
| Goodwill [Line Items] | ||
| Gross Carrying Amount | 16 | 16 |
| Accumulated Amortization | 16 | 16 |
| Other intangible assets | ||
| Goodwill [Line Items] | ||
| Gross Carrying Amount | 154 | 154 |
| Accumulated Amortization | $ 150 | $ 141 |
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- Definition Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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