Investments in Securities - Investments in Securities (Details) - USD ($) $ in Millions |
Dec. 31, 2019 |
Dec. 31, 2018 |
|---|---|---|
| Investments, Debt and Equity Securities [Abstract] | ||
| Trading Securities | $ 49,537 | $ 35,548 |
| Available-for-sale, at fair value | 26,174 | 33,563 |
| Total | $ 75,711 | $ 69,111 |