Guarantees and Contingent Liabilities - Additional Information (Details) - USD ($) $ in Millions |
Jun. 30, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Guarantor Obligations [Line Items] | ||
| Contract or notional amounts of unfunded commitments to extend credit | $ 457,900 | $ 444,700 |
| Reverse Repurchase Agreements | ||
| Guarantor Obligations [Line Items] | ||
| Amount of unfunded contractual commitments | 16,600 | 8,500 |
| Repurchase Agreements | ||
| Guarantor Obligations [Line Items] | ||
| Amount of unfunded contractual commitments | 19,800 | 4,800 |
| Airline Processing Arrangements | ||
| Guarantor Obligations [Line Items] | ||
| Value of airline tickets purchased to deliver at future date through card transactions | 15,100 | |
| Amount reserved for guaranteed obligations | 30 | |
| Airline Processing Arrangements | Escrow Deposits Letters of Credit Indemnities | ||
| Guarantor Obligations [Line Items] | ||
| Collateral held for guaranteed obligations | 358 | |
| Representation and Warranty | ||
| Guarantor Obligations [Line Items] | ||
| Amount reserved for guaranteed obligations | 7 | 7 |
| Unresolved claims | $ 16 | $ 13 |