Segment Reporting (Details) $ in Millions	3 Months Ended
	Mar. 31, 2022 USD ($) segment	Mar. 31, 2021 USD ($)
Segment Reporting Information [Line Items]
Number of reportable business segments | segment	2
Net interest income	$ 7,399	$ 6,742
Fee and other income	83	87
Net revenues	7,482	6,829
Investment gains (losses), net	(102)	45
Fair value gains, net	480	784
Administrative expenses	(808)	(748)
Benefit (provision) for credit losses	(240)	765
Foreclosed property income (expense)	39	5
Total credit-related income (expense)	(201)	770
TCCA fees	(824)	(731)
Credit enhancement expense	(278)	(284)
Change in expected credit enhancement recoveries	60	(31)
Other expenses, net	(236)	(319)
Income before federal income taxes	5,573	6,315
Provision for federal income taxes	(1,165)	(1,322)
Net income	4,408	4,993
US Treasury
Segment Reporting Information [Line Items]
TCCA fees	(824)	(731)
Business segments | Single Family
Segment Reporting Information [Line Items]
Net interest income	6,255	5,894
Fee and other income	61	62
Net revenues	6,316	5,956
Investment gains (losses), net	(66)	64
Fair value gains, net	527	740
Administrative expenses	(683)	(623)
Benefit (provision) for credit losses	(270)	662
Foreclosed property income (expense)	34	17
Total credit-related income (expense)	(236)	679
Credit enhancement expense	(210)	(226)
Change in expected credit enhancement recoveries	69	(16)
Other expenses, net	(198)	(287)
Income before federal income taxes	4,695	5,556
Provision for federal income taxes	(986)	(1,162)
Net income	3,709	4,394
Business segments | Single Family | US Treasury
Segment Reporting Information [Line Items]
TCCA fees	(824)	(731)
Business segments | Multifamily
Segment Reporting Information [Line Items]
Net interest income	1,144	848
Fee and other income	22	25
Net revenues	1,166	873
Investment gains (losses), net	(36)	(19)
Fair value gains, net	(47)	44
Administrative expenses	(125)	(125)
Benefit (provision) for credit losses	30	103
Foreclosed property income (expense)	5	(12)
Total credit-related income (expense)	35	91
Credit enhancement expense	(68)	(58)
Change in expected credit enhancement recoveries	(9)	(15)
Other expenses, net	(38)	(32)
Income before federal income taxes	878	759
Provision for federal income taxes	(179)	(160)
Net income	699	599
Business segments | Multifamily | US Treasury
Segment Reporting Information [Line Items]
TCCA fees	$ 0	$ 0