Investments in Securities - Trading 1 (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	$ 84,629	$ 88,206
Mortgage-related securities
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	4,626	4,606
Fannie Mae
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	1,789	1,576
Other agency
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	2,710	2,893
Private-label and other mortgage securities
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	127	137
Total non-mortgage-related securities
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	80,003	83,600
U.S. Treasury securities
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	79,987	83,581
Other securities
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	16	19
Consolidated trusts
Schedule of Investments in Trading Securities [Line Items]
Trading, at fair value	$ 499	$ 593