Mortgage Loans - Non-accrual Loans (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022	Dec. 31, 2021
Financing Receivable, Nonaccrual [Line Items]
Recorded investment in nonaccrual loans	$ 16,818	$ 16,278	$ 12,517	$ 20,496
Total interest income recognized	38	56
Single-family
Financing Receivable, Nonaccrual [Line Items]
Accrued interest receivable written off through the reversal of interest income:	79	17
Recorded investment in nonaccrual loans	15,277	15,020	10,317	19,237
Total interest income recognized	9	51
Single-family | 20- and 30-year or more, amortizing fixed-rate
Financing Receivable, Nonaccrual [Line Items]
Recorded investment in nonaccrual loans	14,172	13,692	9,447	17,599
Total interest income recognized	7	47
Single-family | 15-year or less, amortizing fixed-rate
Financing Receivable, Nonaccrual [Line Items]
Recorded investment in nonaccrual loans	429	331	200	430
Total interest income recognized	0	1
Single-family | Adjustable-rate
Financing Receivable, Nonaccrual [Line Items]
Recorded investment in nonaccrual loans	75	84	53	107
Total interest income recognized	0	0
Single-family | Other
Financing Receivable, Nonaccrual [Line Items]
Recorded investment in nonaccrual loans	601	913	617	1,101
Total interest income recognized	2	3
Multifamily
Financing Receivable, Nonaccrual [Line Items]
Accrued interest receivable written off through the reversal of interest income:	2	1
Recorded investment in nonaccrual loans	1,541	1,258	$ 2,200	$ 1,259
Total interest income recognized	$ 29	$ 5