Collateralized Agreements and Financings - Financial Instruments Received as Collateral and Repledged (Detail) - USD ($) $ in Millions |
Mar. 31, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Collateralized Agreements And Financings [Abstract] | ||
| Collateral available to be delivered or repledged | $ 1,390,755 | $ 1,312,079 |
| Collateral that was delivered or repledged | $ 1,223,841 | $ 1,119,825 |