Mortgage Loans - Credit Quality Indicators - SF (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Restructured loans, amortized cost	$ 17,934	$ 27,527	$ 28,452	$ 46,491
Restructured loans, percent of total financing receivable		1.00%	1.00%	1.00%
Forbearance Plan
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Restructured loans, amortized cost	9,004	$ 12,099	$ 11,837	$ 15,803
Payment Deferral
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Restructured loans, amortized cost	2,851	5,638	6,582	12,552
Trial Modification and Repayment Plans
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Restructured loans, amortized cost	3,674	4,141	5,557	6,602
Payment Delay and Term Extension
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Restructured loans, amortized cost	1,782	815	3,557	1,971
Payment Delay, Term Extension and Interest Rate Reduction
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Restructured loans, amortized cost	623	4,834	919	9,563
Single-family
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]
Current fiscal year	128,930		128,930		$ 497,393
One fiscal year before	505,405		505,405		1,185,382
Two fiscal years before	1,144,064		1,144,064		963,992
Three fiscal years before	926,332		926,332		171,549
Four fiscal years before	163,277		163,277		79,469
Prior	815,650		815,650		790,243
Total mortgage loans	3,683,658		3,683,658		3,688,028
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Current fiscal year, writeoff			0
One fiscal year, writeoff			9
Two fiscal years, writeoff			20
Three fiscal years, writeoff			12
Four fiscal years, writeoff			6
Prior			45
Total writeoff			92
Restructured loans, amortized cost	16,986	$ 27,493	$ 27,134	$ 46,243
Restructured loans, percent of total financing receivable		1.00%	1.00%	1.00%
Single-family | Forbearance Plan
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Restructured loans, amortized cost	8,581	$ 12,076	$ 11,053	$ 15,566
Single-family | Payment Deferral
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Restructured loans, amortized cost	2,851	5,638	6,582	12,552
Single-family | Trial Modification and Repayment Plans
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Restructured loans, amortized cost	3,674	4,141	5,557	6,602
Single-family | Payment Delay and Term Extension
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Restructured loans, amortized cost	1,782	815	3,557	1,971
Single-family | Payment Delay, Term Extension and Interest Rate Reduction
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Restructured loans, amortized cost	98	4,823	385	9,552
Single-family | Less than or equal to 80%
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]
Current fiscal year	75,094		75,094		323,058
One fiscal year before	350,161		350,161		1,088,871
Two fiscal years before	1,085,197		1,085,197		956,653
Three fiscal years before	921,329		921,329		170,156
Four fiscal years before	162,131		162,131		78,758
Prior	813,595		813,595		788,467
Total mortgage loans	3,407,507		3,407,507		3,405,963
Single-family | Greater than 80% and less than or equal to 90%
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]
Current fiscal year	22,873		22,873		87,240
One fiscal year before	102,346		102,346		86,981
Two fiscal years before	53,702		53,702		5,949
Three fiscal years before	4,171		4,171		1,158
Four fiscal years before	1,015		1,015		620
Prior	1,492		1,492		1,196
Total mortgage loans	185,599		185,599		183,144
Single-family | Greater than 90% and less than or equal to 100%
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]
Current fiscal year	30,943		30,943		85,861
One fiscal year before	52,062		52,062		9,321
Two fiscal years before	4,946		4,946		1,334
Three fiscal years before	762		762		217
Four fiscal years before	110		110		79
Prior	306		306		281
Total mortgage loans	89,129		89,129		97,093
Single-family | Greater than 100%
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]
Current fiscal year	20		20		1,234
One fiscal year before	836		836		209
Two fiscal years before	219		219		56
Three fiscal years before	70		70		18
Four fiscal years before	21		21		12
Prior	257		257		299
Total mortgage loans	1,423		1,423		1,828
Single-family | 20- and 30-year or more, amortizing fixed-rate
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]
Current fiscal year	122,920		122,920		452,015
One fiscal year before	461,140		461,140		992,804
Two fiscal years before	962,281		962,281		827,745
Three fiscal years before	798,728		798,728		150,454
Four fiscal years before	143,860		143,860		71,013
Prior	686,782		686,782		652,823
Total mortgage loans	3,175,711		3,175,711		3,146,854
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Current fiscal year, writeoff			0
One fiscal year, writeoff			9
Two fiscal years, writeoff			20
Three fiscal years, writeoff			12
Four fiscal years, writeoff			6
Prior			33
Total writeoff			80
Restructured loans, amortized cost	$ 16,066	$ 25,671	$ 25,644	$ 43,006
Restructured loans, percent of total financing receivable	1.00%	1.00%	1.00%	1.00%
Single-family | 20- and 30-year or more, amortizing fixed-rate | Forbearance Plan
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Restructured loans, amortized cost	$ 8,107	$ 11,213	$ 10,410	$ 14,428
Single-family | 20- and 30-year or more, amortizing fixed-rate | Payment Deferral
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Restructured loans, amortized cost	2,689	5,203	6,207	11,518
Single-family | 20- and 30-year or more, amortizing fixed-rate | Trial Modification and Repayment Plans
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Restructured loans, amortized cost	3,444	3,815	5,202	6,064
Single-family | 20- and 30-year or more, amortizing fixed-rate | Payment Delay and Term Extension
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Restructured loans, amortized cost	1,746	769	3,487	1,831
Single-family | 20- and 30-year or more, amortizing fixed-rate | Payment Delay, Term Extension and Interest Rate Reduction
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Restructured loans, amortized cost	80	4,671	338	9,165
Single-family | 20- and 30-year or more, amortizing fixed-rate | Less than or equal to 80%
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]
Current fiscal year	70,043		70,043		281,257
One fiscal year before	308,622		308,622		896,977
Two fiscal years before	903,688		903,688		820,452
Three fiscal years before	793,746		793,746		149,067
Four fiscal years before	142,716		142,716		70,306
Prior	684,941		684,941		651,297
Total mortgage loans	2,903,756		2,903,756		2,869,356
Single-family | 20- and 30-year or more, amortizing fixed-rate | Greater than 80% and less than or equal to 90%
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]
Current fiscal year	22,294		22,294		84,864
One fiscal year before	100,199		100,199		86,335
Two fiscal years before	53,443		53,443		5,904
Three fiscal years before	4,152		4,152		1,152
Four fiscal years before	1,013		1,013		618
Prior	1,379		1,379		1,062
Total mortgage loans	182,480		182,480		179,935
Single-family | 20- and 30-year or more, amortizing fixed-rate | Greater than 90% and less than or equal to 100%
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]
Current fiscal year	30,563		30,563		84,664
One fiscal year before	51,485		51,485		9,284
Two fiscal years before	4,932		4,932		1,333
Three fiscal years before	760		760		217
Four fiscal years before	110		110		77
Prior	255		255		224
Total mortgage loans	88,105		88,105		95,799
Single-family | 20- and 30-year or more, amortizing fixed-rate | Greater than 100%
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]
Current fiscal year	20		20		1,230
One fiscal year before	834		834		208
Two fiscal years before	218		218		56
Three fiscal years before	70		70		18
Four fiscal years before	21		21		12
Prior	207		207		240
Total mortgage loans	1,370		1,370		1,764
Single-family | 15-year or less, amortizing fixed-rate
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]
Current fiscal year	4,531		4,531		39,748
One fiscal year before	38,174		38,174		185,938
Two fiscal years before	175,447		175,447		134,370
Three fiscal years before	125,835		125,835		20,242
Four fiscal years before	18,624		18,624		7,324
Prior	96,882		96,882		103,846
Total mortgage loans	459,493		459,493		491,468
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Current fiscal year, writeoff			0
One fiscal year, writeoff			0
Two fiscal years, writeoff			0
Three fiscal years, writeoff			0
Four fiscal years, writeoff			0
Prior			1
Total writeoff			1
Restructured loans, amortized cost	588	1,012	919	1,643
Single-family | 15-year or less, amortizing fixed-rate | Forbearance Plan
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Restructured loans, amortized cost	339	571	451	735
Single-family | 15-year or less, amortizing fixed-rate | Payment Deferral
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Restructured loans, amortized cost	116	287	264	653
Single-family | 15-year or less, amortizing fixed-rate | Trial Modification and Repayment Plans
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Restructured loans, amortized cost	132	154	203	253
Single-family | 15-year or less, amortizing fixed-rate | Payment Delay and Term Extension
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Restructured loans, amortized cost	1	0	1	1
Single-family | 15-year or less, amortizing fixed-rate | Payment Delay, Term Extension and Interest Rate Reduction
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Restructured loans, amortized cost	0	0	0	1
Single-family | 15-year or less, amortizing fixed-rate | Less than or equal to 80%
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]
Current fiscal year	4,075		4,075		37,830
One fiscal year before	37,021		37,021		185,511
Two fiscal years before	175,317		175,317		134,336
Three fiscal years before	125,822		125,822		20,239
Four fiscal years before	18,623		18,623		7,324
Prior	96,878		96,878		103,841
Total mortgage loans	457,736		457,736		489,081
Single-family | 15-year or less, amortizing fixed-rate | Greater than 80% and less than or equal to 90%
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]
Current fiscal year	281		281		1,363
One fiscal year before	1,010		1,010		410
Two fiscal years before	126		126		33
Three fiscal years before	12		12		3
Four fiscal years before	1		1		0
Prior	2		2		2
Total mortgage loans	1,432		1,432		1,811
Single-family | 15-year or less, amortizing fixed-rate | Greater than 90% and less than or equal to 100%
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]
Current fiscal year	175		175		552
One fiscal year before	143		143		16
Two fiscal years before	4		4		1
Three fiscal years before	1		1		0
Four fiscal years before	0		0		0
Prior	1		1		1
Total mortgage loans	324		324		570
Single-family | 15-year or less, amortizing fixed-rate | Greater than 100%
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]
Current fiscal year	0		0		3
One fiscal year before	0		0		1
Two fiscal years before	0		0		0
Three fiscal years before	0		0		0
Four fiscal years before	0		0		0
Prior	1		1		2
Total mortgage loans	1		1		6
Single-family | Adjustable-rate
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]
Current fiscal year	1,479		1,479		5,630
One fiscal year before	6,091		6,091		6,640
Two fiscal years before	6,336		6,336		1,877
Three fiscal years before	1,769		1,769		824
Four fiscal years before	765		765		908
Prior	10,870		10,870		11,229
Total mortgage loans	27,310		27,310		27,108
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Current fiscal year, writeoff			0
One fiscal year, writeoff			0
Two fiscal years, writeoff			0
Three fiscal years, writeoff			0
Four fiscal years, writeoff			0
Prior			0
Total writeoff			0
Restructured loans, amortized cost	69	120	102	$ 226
Restructured loans, percent of total financing receivable				1.00%
Single-family | Adjustable-rate | Forbearance Plan
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Restructured loans, amortized cost	46	61	55	$ 84
Single-family | Adjustable-rate | Payment Deferral
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Restructured loans, amortized cost	10	27	27	77
Single-family | Adjustable-rate | Trial Modification and Repayment Plans
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Restructured loans, amortized cost	12	28	18	53
Single-family | Adjustable-rate | Payment Delay and Term Extension
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Restructured loans, amortized cost	0	0	0	0
Single-family | Adjustable-rate | Payment Delay, Term Extension and Interest Rate Reduction
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Restructured loans, amortized cost	1	4	2	12
Single-family | Adjustable-rate | Less than or equal to 80%
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]
Current fiscal year	976		976		3,971
One fiscal year before	4,518		4,518		6,383
Two fiscal years before	6,192		6,192		1,865
Three fiscal years before	1,761		1,761		821
Four fiscal years before	764		764		906
Prior	10,866		10,866		11,226
Total mortgage loans	25,077		25,077		25,172
Single-family | Adjustable-rate | Greater than 80% and less than or equal to 90%
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]
Current fiscal year	298		298		1,013
One fiscal year before	1,137		1,137		236
Two fiscal years before	133		133		12
Three fiscal years before	7		7		3
Four fiscal years before	1		1		1
Prior	4		4		3
Total mortgage loans	1,580		1,580		1,268
Single-family | Adjustable-rate | Greater than 90% and less than or equal to 100%
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]
Current fiscal year	205		205		645
One fiscal year before	434		434		21
Two fiscal years before	10		10		0
Three fiscal years before	1		1		0
Four fiscal years before	0		0		1
Prior	0		0		0
Total mortgage loans	650		650		667
Single-family | Adjustable-rate | Greater than 100%
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]
Current fiscal year	0		0		1
One fiscal year before	2		2		0
Two fiscal years before	1		1		0
Three fiscal years before	0		0		0
Four fiscal years before	0		0		0
Prior	0		0		0
Total mortgage loans	3		3		1
Single-family | Other
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]
Current fiscal year	0		0		0
One fiscal year before	0		0		0
Two fiscal years before	0		0		0
Three fiscal years before	0		0		29
Four fiscal years before	28		28		224
Prior	21,116		21,116		22,345
Total mortgage loans	21,144		21,144		22,598
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Current fiscal year, writeoff			0
One fiscal year, writeoff			0
Two fiscal years, writeoff			0
Three fiscal years, writeoff			0
Four fiscal years, writeoff			0
Prior			11
Total writeoff			11
Restructured loans, amortized cost	$ 263	$ 690	$ 469	$ 1,368
Restructured loans, percent of total financing receivable	1.00%	2.00%	2.00%	4.00%
Single-family | Other | Forbearance Plan
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Restructured loans, amortized cost	$ 89	$ 231	$ 137	$ 319
Single-family | Other | Payment Deferral
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Restructured loans, amortized cost	36	121	84	304
Single-family | Other | Trial Modification and Repayment Plans
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Restructured loans, amortized cost	86	144	134	232
Single-family | Other | Payment Delay and Term Extension
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Restructured loans, amortized cost	35	46	69	139
Single-family | Other | Payment Delay, Term Extension and Interest Rate Reduction
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Restructured loans, amortized cost	17	148	45	374
Single-family | Other | Less than or equal to 80%
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]
Current fiscal year	0		0		0
One fiscal year before	0		0		0
Two fiscal years before	0		0		0
Three fiscal years before	0		0		29
Four fiscal years before	28		28		222
Prior	20,910		20,910		22,103
Total mortgage loans	20,938		20,938		22,354
Single-family | Other | Greater than 80% and less than or equal to 90%
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]
Current fiscal year	0		0		0
One fiscal year before	0		0		0
Two fiscal years before	0		0		0
Three fiscal years before	0		0		0
Four fiscal years before	0		0		1
Prior	107		107		129
Total mortgage loans	107		107		130
Single-family | Other | Greater than 90% and less than or equal to 100%
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]
Current fiscal year	0		0		0
One fiscal year before	0		0		0
Two fiscal years before	0		0		0
Three fiscal years before	0		0		0
Four fiscal years before	0		0		1
Prior	50		50		56
Total mortgage loans	50		50		57
Single-family | Other | Greater than 100%
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]
Current fiscal year	0		0		0
One fiscal year before	0		0		0
Two fiscal years before	0		0		0
Three fiscal years before	0		0		0
Four fiscal years before	0		0		0
Prior	49		49		57
Total mortgage loans	49		49		57
Single-family | U.S Government
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]
Total mortgage loans	7,100		7,100		$ 9,500
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Total writeoff	3
Multifamily
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Restructured loans, amortized cost	948	34	1,318	248
Multifamily | Forbearance Plan
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Restructured loans, amortized cost	423	23	784	237
Multifamily | Payment Deferral
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Restructured loans, amortized cost	0	0	0	0
Multifamily | Trial Modification and Repayment Plans
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Restructured loans, amortized cost	0	0	0	0
Multifamily | Payment Delay and Term Extension
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Restructured loans, amortized cost	0	0	0	0
Multifamily | Payment Delay, Term Extension and Interest Rate Reduction
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
Restructured loans, amortized cost	$ 525	$ 11	$ 534	$ 11