Mortgage Loans - Loans in Mortgage Portfolio (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Loans in Mortgage Portfolio [Line Items]
Unpaid principal balance of mortgage loans	$ 4,075,598	$ 3,899,025
Cost basis and fair value adjustments, net	50,185	74,846
Allowance for loan losses	(11,347)	(5,629)	$ (10,552)	$ (9,016)
Total mortgage loans	4,114,436	3,968,242
Accrued interest receivable, net	9,821	9,264
Mortgage loans
Loans in Mortgage Portfolio [Line Items]
Accrued interest receivable, net	9,500	9,100
Single-family
Loans in Mortgage Portfolio [Line Items]
Unpaid principal balance of mortgage loans	3,644,158	3,495,573
Purchase of HFI loans	614,836	1,354,705	1,358,744
Single family loans redesignated from HFI to HFS, amortized cost	7,825	16,606	8,309
Single family loans redesignated from HFI to HFS, lower of cost or fair value adjustment at time of redesignation	(679)	(372)	(291)
Single family loans redesignated from HFI to HFS, allowance reversed at time of redesignation	373	1,605	963
Single family loans redesignated from HFS to HFI, amortized cost	2,004	5	144
Single-family loans sold, unpaid principal balance	8,069	16,977	9,519
Single-family loans sold, realized gain, net	126	1,624	831
Mortgage loans in process of foreclosure	4,600	4,400
Multifamily
Loans in Mortgage Portfolio [Line Items]
Unpaid principal balance of mortgage loans	431,440	403,452
Purchase of HFI loans	$ 69,206	$ 69,185	$ 75,517