Mortgage Loans - Credit Quality Indicators - SF (Details) - Single-family - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Financing Receivable, Credit Quality Indicator [Line Items]
2022	$ 309,769	$ 1,200,915
2021	1,231,226	1,082,870
2020	1,009,012	207,663
2019	182,408	100,239
2018	85,518	135,670
Prior	854,211	829,967
Total mortgage loans	3,672,144	3,557,324
Estimated mark-to-market loan-to-value ratio less than or equal to 80%
Financing Receivable, Credit Quality Indicator [Line Items]
2022	223,655	1,001,159
2021	1,140,781	1,040,601
2020	1,002,153	204,398
2019	180,978	98,924
2018	84,791	134,953
Prior	852,087	826,785
Total mortgage loans	3,484,445	3,306,820
Estimated mark-to-market loan-to-value ratio greater than 80% and less than or equal to 90%
Financing Receivable, Credit Quality Indicator [Line Items]
2022	48,828	132,354
2021	84,974	39,973
2020	5,578	2,712
2019	1,044	1,067
2018	611	632
Prior	1,419	1,972
Total mortgage loans	142,454	178,710
Estimated mark-to-market loan-to-value ratio greater than 90% and less than or equal to 100%
Financing Receivable, Credit Quality Indicator [Line Items]
2022	37,285	67,381
2021	5,460	2,284
2020	1,272	544
2019	375	231
2018	103	60
Prior	346	597
Total mortgage loans	44,841	71,097
Estimated mark-to-market loan-to-value ratio greater than 100%
Financing Receivable, Credit Quality Indicator [Line Items]
2022	1	21
2021	11	12
2020	9	9
2019	11	17
2018	13	25
Prior	359	613
Total mortgage loans	404	697
20- and 30-year or more, amortizing fixed-rate
Financing Receivable, Credit Quality Indicator [Line Items]
2022	274,639	994,858
2021	1,026,962	923,269
2020	863,028	181,151
2019	159,308	89,126
2018	76,108	111,760
Prior	697,325	668,941
Total mortgage loans	3,097,370	2,969,105
20- and 30-year or more, amortizing fixed-rate | Estimated mark-to-market loan-to-value ratio less than or equal to 80%
Financing Receivable, Credit Quality Indicator [Line Items]
2022	190,136	798,830
2021	937,515	881,290
2020	856,222	177,909
2019	157,885	87,825
2018	75,387	111,059
Prior	695,506	666,327
Total mortgage loans	2,912,651	2,723,240
20- and 30-year or more, amortizing fixed-rate | Estimated mark-to-market loan-to-value ratio greater than 80% and less than or equal to 90%
Financing Receivable, Credit Quality Indicator [Line Items]
2022	47,716	129,340
2021	84,022	39,689
2020	5,527	2,689
2019	1,037	1,056
2018	606	622
Prior	1,262	1,687
Total mortgage loans	140,170	175,083
20- and 30-year or more, amortizing fixed-rate | Estimated mark-to-market loan-to-value ratio greater than 90% and less than or equal to 100%
Financing Receivable, Credit Quality Indicator [Line Items]
2022	36,786	66,667
2021	5,414	2,278
2020	1,270	544
2019	375	229
2018	102	57
Prior	273	460
Total mortgage loans	44,220	70,235
20- and 30-year or more, amortizing fixed-rate | Estimated mark-to-market loan-to-value ratio greater than 100%
Financing Receivable, Credit Quality Indicator [Line Items]
2022	1	21
2021	11	12
2020	9	9
2019	11	16
2018	13	22
Prior	284	467
Total mortgage loans	329	547
15-year or less, amortizing fixed-rate
Financing Receivable, Credit Quality Indicator [Line Items]
2022	32,775	199,318
2021	197,287	157,340
2020	143,967	25,406
2019	22,174	9,600
2018	8,166	20,720
Prior	119,595	121,043
Total mortgage loans	523,964	533,427
15-year or less, amortizing fixed-rate | Estimated mark-to-market loan-to-value ratio less than or equal to 80%
Financing Receivable, Credit Quality Indicator [Line Items]
2022	31,599	196,163
2021	196,511	157,076
2020	143,922	25,390
2019	22,168	9,595
2018	8,165	20,715
Prior	119,586	121,027
Total mortgage loans	521,951	529,966
15-year or less, amortizing fixed-rate | Estimated mark-to-market loan-to-value ratio greater than 80% and less than or equal to 90%
Financing Receivable, Credit Quality Indicator [Line Items]
2022	802	2,576
2021	745	259
2020	44	16
2019	6	4
2018	1	2
Prior	3	7
Total mortgage loans	1,601	2,864
15-year or less, amortizing fixed-rate | Estimated mark-to-market loan-to-value ratio greater than 90% and less than or equal to 100%
Financing Receivable, Credit Quality Indicator [Line Items]
2022	374	579
2021	31	5
2020	1	0
2019	0	1
2018	0	1
Prior	2	4
Total mortgage loans	408	590
15-year or less, amortizing fixed-rate | Estimated mark-to-market loan-to-value ratio greater than 100%
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	0	0
2018	0	2
Prior	4	5
Total mortgage loans	4	7
Adjustable-rate
Financing Receivable, Credit Quality Indicator [Line Items]
2022	2,355	6,739
2021	6,977	2,261
2020	2,017	1,072
2019	895	1,240
2018	1,003	2,526
Prior	12,701	12,504
Total mortgage loans	25,948	26,342
Adjustable-rate | Estimated mark-to-market loan-to-value ratio less than or equal to 80%
Financing Receivable, Credit Quality Indicator [Line Items]
2022	1,920	6,166
2021	6,755	2,235
2020	2,009	1,065
2019	894	1,236
2018	1,001	2,524
Prior	12,698	12,501
Total mortgage loans	25,277	25,727
Adjustable-rate | Estimated mark-to-market loan-to-value ratio greater than 80% and less than or equal to 90%
Financing Receivable, Credit Quality Indicator [Line Items]
2022	310	438
2021	207	25
2020	7	7
2019	1	4
2018	2	2
Prior	3	3
Total mortgage loans	530	479
Adjustable-rate | Estimated mark-to-market loan-to-value ratio greater than 90% and less than or equal to 100%
Financing Receivable, Credit Quality Indicator [Line Items]
2022	125	135
2021	15	1
2020	1	0
2019	0	0
2018	0	0
Prior	0	0
Total mortgage loans	141	136
Adjustable-rate | Estimated mark-to-market loan-to-value ratio greater than 100%
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	0	0
2018	0	0
Prior	0	0
Total mortgage loans	0	0
Other
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	34
2019	31	273
2018	241	664
Prior	24,590	27,479
Total mortgage loans	24,862	28,450
Other | Estimated mark-to-market loan-to-value ratio less than or equal to 80%
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	34
2019	31	268
2018	238	655
Prior	24,297	26,930
Total mortgage loans	24,566	27,887
Other | Estimated mark-to-market loan-to-value ratio greater than 80% and less than or equal to 90%
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	0	3
2018	2	6
Prior	151	275
Total mortgage loans	153	284
Other | Estimated mark-to-market loan-to-value ratio greater than 90% and less than or equal to 100%
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	0	1
2018	1	2
Prior	71	133
Total mortgage loans	72	136
Other | Estimated mark-to-market loan-to-value ratio greater than 100%
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0	0
2021	0	0
2020	0	0
2019	0	1
2018	0	1
Prior	71	141
Total mortgage loans	71	143
U.S Government
Financing Receivable, Credit Quality Indicator [Line Items]
Total mortgage loans	$ 8,800	$ 9,500