Credit Concentrations - Credit Concentration, Government and Federal Agency Obligations (Detail) - USD ($) $ in Millions |
12 Months Ended | |
|---|---|---|
Dec. 31, 2021 |
Dec. 31, 2020 |
|
| U.S. Government and Agency Obligations Held By The Firm [Member] | ||
| Concentration Risk [Line Items] | ||
| Concentration risk, Credit risk, Financial instrument, Maximum exposure | $ 141,191 | $ 187,009 |
| Concentration risk, Credit risk, Financial instrument, Maximum exposure, As a percentage of total Assets | 9.60% | 16.10% |
| Non-U.S. Government and Agency Obligations Held By The Firm [Member] | ||
| Concentration Risk [Line Items] | ||
| Concentration risk, Credit risk, Financial instrument, Maximum exposure | $ 51,426 | $ 59,580 |
| Concentration risk, Credit risk, Financial instrument, Maximum exposure, As a percentage of total Assets | 3.50% | 5.10% |