Commitments, Contingencies and Guarantees (Credit Risk Of Financial Instruments By Contractual Amounts) (Details) - USD ($) $ in Millions |
Mar. 31, 2024 |
Dec. 31, 2023 |
Mar. 31, 2023 |
Dec. 31, 2022 |
|---|---|---|---|---|
| Other Commitments [Line Items] | ||||
| Unused commitments to extend credit | $ 63,676 | $ 63,631 | ||
| Standby letters of credit | 2,082 | 1,997 | ||
| Commercial letters of credit | 78 | 78 | ||
| Liabilities associated with standby letters of credit | 31 | 32 | ||
| Assets associated with standby letters of credit | 33 | 34 | ||
| Reserve for unfunded credit commitments | $ 114 | $ 124 | $ 124 | $ 118 |