Deposits - Types and Sources of the Firm's Deposits (Detail) - USD ($) $ in Millions |
Sep. 30, 2021 |
Dec. 31, 2020 |
|---|---|---|
| Deposits [Line Items] | ||
| Savings and demand | $ 235,620 | $ 186,419 |
| Time | 97,418 | 73,543 |
| Total | 333,038 | 259,962 |
| Consumer [Member] | ||
| Deposits [Line Items] | ||
| Savings and demand | 83,584 | 67,395 |
| Time | 21,889 | 29,530 |
| Total | 105,473 | 96,925 |
| Private Bank [Member] | ||
| Deposits [Line Items] | ||
| Savings and demand | 75,012 | 67,185 |
| Time | 3,363 | 1,183 |
| Total | 78,375 | 68,368 |
| Brokered Certificates Of Deposit [Member] | ||
| Deposits [Line Items] | ||
| Savings and demand | 0 | 0 |
| Time | 31,508 | 30,060 |
| Total | 31,508 | 30,060 |
| Deposit Sweep Programs [Member] | ||
| Deposits [Line Items] | ||
| Savings and demand | 31,260 | 22,987 |
| Time | 0 | 0 |
| Total | 31,260 | 22,987 |
| Transaction Banking [Member] | ||
| Deposits [Line Items] | ||
| Savings and demand | 45,764 | 28,852 |
| Time | 5,628 | 0 |
| Total | 51,392 | 28,852 |
| Other [Member] | ||
| Deposits [Line Items] | ||
| Savings and demand | 0 | 0 |
| Time | 35,030 | 12,770 |
| Total | $ 35,030 | $ 12,770 |