Collateralized Agreements and Financings - Financial Instruments Received as Collateral and Repledged (Detail) - USD ($) $ in Millions |
Jun. 30, 2021 |
Dec. 31, 2020 |
|---|---|---|
| Collateralized Agreements And Financings [Abstract] | ||
| Financial instruments at fair value received as collateral by the firm that it was permitted to deliver or repledge | $ 1,010,547 | $ 864,494 |
| Financial instruments at fair value received as collateral which the firm delivered or repledged | $ 853,216 | $ 723,409 |