Investments - Summary of Carrying Value of Total Investments (Detail) - USD ($) $ in Millions |
Dec. 31, 2020 |
Dec. 31, 2019 |
||
|---|---|---|---|---|
| Schedule of Investments [Line Items] | ||||
| Held-to-maturity investments | $ 310 | $ 249 | ||
| Trading securities | 1,964 | 1,249 | ||
| Total debt securities | 2,274 | 1,498 | ||
| Equity securities at FVTNI | 2,317 | 1,926 | ||
| Total investments | [1] | 6,919 | 5,489 | |
| Bank loans | 248 | 204 | ||
| Other Investments [Member] | ||||
| Schedule of Investments [Line Items] | ||||
| Total investments | 278 | 297 | ||
| Equity Method Investments [Member] | ||||
| Schedule of Investments [Line Items] | ||||
| Total investments | 1,081 | 943 | ||
| Federal Reserve Bank Stock [Member] | ||||
| Schedule of Investments [Line Items] | ||||
| Total investments | 94 | 93 | ||
| Consolidated Entities [Member] | Carried Interest [Member] | ||||
| Schedule of Investments [Line Items] | ||||
| Total investments | $ 627 | $ 528 | ||
| ||||