Deposits - Types and Sources of the Firm's Deposits (Parenthetical) (Detail) $ in Millions |
9 Months Ended | 12 Months Ended | |
|---|---|---|---|
|
Sep. 30, 2021
USD ($)
Arrangements
|
Dec. 31, 2020
USD ($)
|
Sep. 30, 2020
USD ($)
|
|
| Deposits [Abstract] | |||
| Deposits at fair value | $ 34,078 | $ 16,176 | $ 34,078 |
| Weighted average maturity of time deposits | 1 year | 1 year 3 months 18 days | |
| Number of deposit sweep program contractual arrangements | Arrangements | 14 | ||
| Deposits insured by the FDIC | $ 148,480 | $ 123,030 | |
| Deposits insured by non-U.S. Insurance Programs | $ 29,900 | $ 27,520 |