Investments - Summary of Carrying Value of Total Investments (Detail) (Parenthetical) - USD ($) $ in Millions |
Dec. 31, 2021 |
Dec. 31, 2020 |
|---|---|---|
| Schedule of Investments [Line Items] | ||
| Trading debt securities | $ 1,186 | $ 1,964 |
| Equity securities | 1,738 | 2,317 |
| Consolidated Sponsored Investment Products [Member] | ||
| Schedule of Investments [Line Items] | ||
| Trading debt securities | 1,140 | $ 1,928 |
| Equity securities | $ 1,485 |