Segment Reporting - Schedule of Segment Reporting (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Segment Reporting Information [Line Items]
Net interest income	$ 7,155	$ 7,268	$ 14,156	$ 14,291
Fee and other income	86	68	170	140
Net revenues	7,241	7,336	14,326	14,431
(Provision) benefit for credit losses	(946)	300	(970)	480
Fair value gains (losses), net	211	447	334	927
Investment gains (losses), net	(8)	(62)	(8)	(40)
Non-interest expense:
Administrative expenses	(847)	(899)	(1,839)	(1,788)
Legislative assessments	(939)	(939)	(1,870)	(1,869)
Credit enhancement expense	(400)	(405)	(879)	(824)
Change in expected credit enhancement recoveries	56	37	50	100
Other income (expense), net	(214)	(211)	(406)	(380)
Total non-interest expense	(2,344)	(2,417)	(4,944)	(4,761)
Income before federal income taxes	4,154	5,604	8,738	11,037
Provision for federal income taxes	(837)	(1,120)	(1,760)	(2,233)
Net income	3,317	4,484	6,978	8,804
Related Party | US Treasury
Non-interest expense:
Legislative assessments	(939)	(939)
US Treasury
Non-interest expense:
Legislative assessments			(1,870)	(1,869)
Business segments | Single-Family
Segment Reporting Information [Line Items]
Net interest income	5,992	6,096	11,858	11,970
Fee and other income	69	51	134	106
Net revenues	6,061	6,147	11,992	12,076
(Provision) benefit for credit losses	(737)	548	(761)	883
Fair value gains (losses), net	197	454	279	938
Investment gains (losses), net	(8)	(70)	(6)	(57)
Non-interest expense:
Administrative expenses	(687)	(750)	(1,499)	(1,493)
Credit enhancement expense	(318)	(333)	(725)	(686)
Change in expected credit enhancement recoveries	19	(47)	(12)	(89)
Other income (expense), net	(162)	(182)	(305)	(332)
Total non-interest expense	(2,066)	(2,241)	(4,379)	(4,449)
Income before federal income taxes	3,447	4,838	7,125	9,391
Provision for federal income taxes	(711)	(983)	(1,471)	(1,929)
Net income	2,736	3,855	5,654	7,462
Business segments | Single-Family | Related Party | US Treasury
Non-interest expense:
Legislative assessments	(918)	(929)
Business segments | Single-Family | US Treasury
Non-interest expense:
Legislative assessments			(1,838)	(1,849)
Business segments | Multifamily
Segment Reporting Information [Line Items]
Net interest income	1,163	1,172	2,298	2,321
Fee and other income	17	17	36	34
Net revenues	1,180	1,189	2,334	2,355
(Provision) benefit for credit losses	(209)	(248)	(209)	(403)
Fair value gains (losses), net	14	(7)	55	(11)
Investment gains (losses), net	0	8	(2)	17
Non-interest expense:
Administrative expenses	(160)	(149)	(340)	(295)
Credit enhancement expense	(82)	(72)	(154)	(138)
Change in expected credit enhancement recoveries	37	84	62	189
Other income (expense), net	(52)	(29)	(101)	(48)
Total non-interest expense	(278)	(176)	(565)	(312)
Income before federal income taxes	707	766	1,613	1,646
Provision for federal income taxes	(126)	(137)	(289)	(304)
Net income	581	629	1,324	1,342
Business segments | Multifamily | Related Party | US Treasury
Non-interest expense:
Legislative assessments	$ (21)	$ (10)
Business segments | Multifamily | US Treasury
Non-interest expense:
Legislative assessments			$ (32)	$ (20)