Deposits - Types and Sources of the Firm's Deposits (Detail) - USD ($) $ in Millions |
Dec. 31, 2020 |
Dec. 31, 2019 |
|---|---|---|
| Deposits [Line Items] | ||
| Savings and demand | $ 186,419 | $ 118,750 |
| Time | 73,543 | 71,269 |
| Total | 259,962 | 190,019 |
| Consumer Deposits [Member] | ||
| Deposits [Line Items] | ||
| Savings and demand | 67,395 | 44,973 |
| Time | 29,530 | 15,023 |
| Total | 96,925 | 59,996 |
| Private Bank Deposits [Member] | ||
| Deposits [Line Items] | ||
| Savings and demand | 67,185 | 53,726 |
| Time | 1,183 | 2,087 |
| Total | 68,368 | 55,813 |
| Brokered Certificates Of Deposit [Member] | ||
| Deposits [Line Items] | ||
| Time | 30,060 | 39,449 |
| Total | 30,060 | 39,449 |
| Deposit Sweep Programs [Member] | ||
| Deposits [Line Items] | ||
| Savings and demand | 22,987 | 17,760 |
| Total | 22,987 | 17,760 |
| Transaction Banking [Member] | ||
| Deposits [Line Items] | ||
| Savings and demand | 28,852 | 2,291 |
| Time | 235 | |
| Total | 28,852 | 2,526 |
| Other Deposits [Member] | ||
| Deposits [Line Items] | ||
| Time | 12,770 | 14,475 |
| Total | $ 12,770 | $ 14,475 |