Segment Reporting (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($) segment	Sep. 30, 2021 USD ($)
Segment Reporting Information [Line Items]
Number of reportable business segments | segment			2
Net interest income	$ 7,124	$ 6,972	$ 22,331	$ 22,000
Fee and other income	105	111	269	301
Net revenues	7,229	7,083	22,600	22,301
Investment gains (losses), net	(172)	243	(323)	934
Fair value gains (losses), net	292	(17)	1,301	321
Administrative expenses	(870)	(745)	(2,473)	(2,239)
Benefit (provision) for credit losses	(2,536)	937	(2,994)	4,290
Foreclosed property income (expense)	15	(69)	21	(105)
Total credit-related income (expense)	(2,521)	868	(2,973)	4,185
TCCA fees	(850)	(781)	(2,515)	(2,270)
Credit enhancement expense	(364)	(233)	(974)	(791)
Change in expected credit enhancement recoveries	290	(42)	303	(117)
Other expenses, net	(169)	(268)	(633)	(867)
Income before federal income taxes	2,865	6,108	14,313	21,457
Provision for federal income taxes	(429)	(1,266)	(2,816)	(4,470)
Net income	2,436	4,842	11,497	16,987
US Treasury
Segment Reporting Information [Line Items]
TCCA fees	(850)	(781)	(2,515)	(2,270)
Business segments | Single Family
Segment Reporting Information [Line Items]
Net interest income	5,918	5,870	18,746	19,087
Fee and other income	83	86	204	228
Net revenues	6,001	5,956	18,950	19,315
Investment gains (losses), net	(178)	222	(271)	944
Fair value gains (losses), net	309	(31)	1,379	323
Administrative expenses	(730)	(620)	(2,084)	(1,862)
Benefit (provision) for credit losses	(2,361)	887	(2,837)	4,102
Foreclosed property income (expense)	(6)	(80)	3	(91)
Total credit-related income (expense)	(2,367)	807	(2,834)	4,011
Credit enhancement expense	(298)	(174)	(778)	(619)
Change in expected credit enhancement recoveries	245	(28)	271	(101)
Other expenses, net	(159)	(261)	(556)	(863)
Income before federal income taxes	1,973	5,090	11,562	18,878
Provision for federal income taxes	(276)	(1,065)	(2,270)	(3,952)
Net income	1,697	4,025	9,292	14,926
Business segments | Single Family | US Treasury
Segment Reporting Information [Line Items]
TCCA fees	(850)	(781)	(2,515)	(2,270)
Business segments | Multifamily
Segment Reporting Information [Line Items]
Net interest income	1,206	1,102	3,585	2,913
Fee and other income	22	25	65	73
Net revenues	1,228	1,127	3,650	2,986
Investment gains (losses), net	6	21	(52)	(10)
Fair value gains (losses), net	(17)	14	(78)	(2)
Administrative expenses	(140)	(125)	(389)	(377)
Benefit (provision) for credit losses	(175)	50	(157)	188
Foreclosed property income (expense)	21	11	18	(14)
Total credit-related income (expense)	(154)	61	(139)	174
Credit enhancement expense	(66)	(59)	(196)	(172)
Change in expected credit enhancement recoveries	45	(14)	32	(16)
Other expenses, net	(10)	(7)	(77)	(4)
Income before federal income taxes	892	1,018	2,751	2,579
Provision for federal income taxes	(153)	(201)	(546)	(518)
Net income	739	817	2,205	2,061
Business segments | Multifamily | US Treasury
Segment Reporting Information [Line Items]
TCCA fees	$ 0	$ 0	$ 0	$ 0