Securitization Activities - Amount of Financial Assets Securitized and Cash Flows Received on Retained Interests (Detail) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2021 |
Jun. 30, 2020 |
Jun. 30, 2021 |
Jun. 30, 2020 |
|
| Transfers and Servicing of Financial Assets [Abstract] | ||||
| Securitization of residential mortgages | $ 4,813 | $ 5,297 | $ 9,751 | $ 8,404 |
| Securitization of commercial mortgages | 5,836 | 2,457 | 11,209 | 7,453 |
| Securitization of other financial assets | 1,162 | 687 | 2,225 | 1,227 |
| Total financial assets securitized | 11,811 | 8,441 | 23,185 | 17,084 |
| Retained interests cash flows | $ 282 | $ 98 | $ 412 | $ 184 |