Segment Reporting (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2022 USD ($) segment	Jun. 30, 2021 USD ($)
Segment Reporting Information [Line Items]
Number of reportable business segments | segment			2
Net interest income	$ 7,808	$ 8,286	$ 15,207	$ 15,028
Fee and other income	81	103	164	190
Net revenues	7,889	8,389	15,371	15,218
Investment gains (losses), net	(49)	646	(151)	691
Fair value gains (losses), net	529	(446)	1,009	338
Administrative expenses	(795)	(746)	(1,603)	(1,494)
Benefit (provision) for credit losses	(218)	2,588	(458)	3,353
Foreclosed property income (expense)	(33)	(41)	6	(36)
Total credit-related income (expense)	(251)	2,547	(452)	3,317
TCCA fees	(841)	(758)	(1,665)	(1,489)
Credit enhancement expense	(332)	(274)	(610)	(558)
Change in expected credit enhancement recoveries	(47)	(44)	13	(75)
Other income (expenses), net	(228)	(280)	(464)	(599)
Income before federal income taxes	5,875	9,034	11,448	15,349
Provision for federal income taxes	(1,222)	(1,882)	(2,387)	(3,204)
Net income	4,653	7,152	9,061	12,145
US Treasury
Segment Reporting Information [Line Items]
TCCA fees	(841)	(758)	(1,665)	(1,489)
Business segments | Single Family
Segment Reporting Information [Line Items]
Net interest income	6,573	7,323	12,828	13,217
Fee and other income	60	80	121	142
Net revenues	6,633	7,403	12,949	13,359
Investment gains (losses), net	(27)	658	(93)	722
Fair value gains (losses), net	543	(386)	1,070	354
Administrative expenses	(671)	(619)	(1,354)	(1,242)
Benefit (provision) for credit losses	(206)	2,553	(476)	3,215
Foreclosed property income (expense)	(25)	(28)	9	(11)
Total credit-related income (expense)	(231)	2,525	(467)	3,204
Credit enhancement expense	(270)	(219)	(480)	(445)
Change in expected credit enhancement recoveries	(43)	(57)	26	(73)
Other income (expenses), net	(199)	(315)	(397)	(602)
Income before federal income taxes	4,894	8,232	9,589	13,788
Provision for federal income taxes	(1,008)	(1,725)	(1,994)	(2,887)
Net income	3,886	6,507	7,595	10,901
Business segments | Single Family | US Treasury
Segment Reporting Information [Line Items]
TCCA fees	(841)	(758)	(1,665)	(1,489)
Business segments | Multifamily
Segment Reporting Information [Line Items]
Net interest income	1,235	963	2,379	1,811
Fee and other income	21	23	43	48
Net revenues	1,256	986	2,422	1,859
Investment gains (losses), net	(22)	(12)	(58)	(31)
Fair value gains (losses), net	(14)	(60)	(61)	(16)
Administrative expenses	(124)	(127)	(249)	(252)
Benefit (provision) for credit losses	(12)	35	18	138
Foreclosed property income (expense)	(8)	(13)	(3)	(25)
Total credit-related income (expense)	(20)	22	15	113
Credit enhancement expense	(62)	(55)	(130)	(113)
Change in expected credit enhancement recoveries	(4)	13	(13)	(2)
Other income (expenses), net	(29)	35	(67)	3
Income before federal income taxes	981	802	1,859	1,561
Provision for federal income taxes	(214)	(157)	(393)	(317)
Net income	767	645	1,466	1,244
Business segments | Multifamily | US Treasury
Segment Reporting Information [Line Items]
TCCA fees	$ 0	$ 0	$ 0	$ 0