Unsecured Borrowings - Unsecured Long-Term Borrowings after Hedging (Detail) - USD ($) $ in Millions |
Dec. 31, 2020 |
Dec. 31, 2019 |
|---|---|---|
| Debt Instrument [Line Items] | ||
| Fixed-rate obligations: At fair value | $ 1,521 | $ 725 |
| Fixed rate obligations at amortized cost | 30,827 | 47,577 |
| Floating-rate obligations: At fair value | 39,390 | 42,936 |
| Floating rate obligations at amortized cost | 141,743 | 115,838 |
| Total | 213,481 | 207,076 |
| Group Inc. [Member] | ||
| Debt Instrument [Line Items] | ||
| Fixed-rate obligations: At fair value | 1,407 | 678 |
| Fixed rate obligations at amortized cost | 27,482 | 44,631 |
| Floating-rate obligations: At fair value | 9,721 | 14,920 |
| Floating rate obligations at amortized cost | 133,312 | 108,359 |
| Total | 171,922 | 168,588 |
| Subsidiaries [Member] | ||
| Debt Instrument [Line Items] | ||
| Fixed-rate obligations: At fair value | 114 | 47 |
| Fixed rate obligations at amortized cost | 3,345 | 2,946 |
| Floating-rate obligations: At fair value | 29,669 | 28,016 |
| Floating rate obligations at amortized cost | 8,431 | 7,479 |
| Total | $ 41,559 | $ 38,488 |