Investments - Summary of Carrying Value of Total Investments (Detail) - USD ($) $ in Millions |
Dec. 31, 2019 |
Dec. 31, 2018 |
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|---|---|---|---|---|
| Schedule of Investments [Line Items] | ||||
| Held-to-maturity investments | $ 249 | $ 188 | ||
| Trading securities | 1,249 | 1,660 | ||
| Total debt securities | 1,498 | 1,848 | ||
| Equity securities at FVTNI | 1,926 | 1,021 | ||
| Total investments | [1] | 5,489 | 4,476 | |
| Bank loans | 204 | 84 | ||
| Other Investments [Member] | ||||
| Schedule of Investments [Line Items] | ||||
| Total investments | 297 | 263 | ||
| Equity Method Investments [Member] | ||||
| Schedule of Investments [Line Items] | ||||
| Total investments | 943 | 781 | ||
| Federal Reserve Bank Stock [Member] | ||||
| Schedule of Investments [Line Items] | ||||
| Total investments | 93 | 92 | ||
| Consolidated Entities [Member] | Carried Interest [Member] | ||||
| Schedule of Investments [Line Items] | ||||
| Total investments | $ 528 | $ 387 | ||
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