Commitments, Contingencies and Guarantees - Lending Commitments (Detail) - USD ($) $ in Millions |
Jun. 30, 2021 |
Dec. 31, 2020 |
|---|---|---|
| Commitments and Contingencies Disclosure [Abstract] | ||
| Held for investment | $ 192,914 | $ 162,513 |
| Held for sale | 15,458 | 6,594 |
| At fair value | 1,639 | 2,468 |
| Total | $ 210,011 | $ 171,575 |