Collateralized Transactions (Amounts Related to Collateralized Transactions) (Details) - USD ($) $ in Millions |
Mar. 31, 2026 |
Dec. 31, 2025 |
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|---|---|---|---|---|
| Permitted To Repledge [Member] | ||||
| Collateralized Transactions [Line Items] | ||||
| Securities lending transactions | [1] | $ 195,112 | $ 197,478 | |
| Securities purchased under agreements to resell transactions | [1] | 42,026 | 24,947 | |
| Customer margin assets | 115,899 | 115,846 | ||
| Total collateralized transactions | 353,037 | 338,271 | ||
| Sold Or Repledged [Member] | ||||
| Collateralized Transactions [Line Items] | ||||
| Securities lending transactions | [1] | 20,294 | 17,204 | |
| Securities purchased under agreements to resell transactions | [1] | 40,682 | 24,225 | |
| Customer margin assets | 38,143 | 31,410 | ||
| Total collateralized transactions | $ 99,119 | $ 72,839 | ||
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