v3.26.1
Mortgage Loans - Credit Quality Indicators - SF (Details) - Single-family - USD ($)
$ in Millions
 3 Months Ended 12 Months Ended
Mar. 31, 2026
Dec. 31, 2025
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]    
Current fiscal year $ 64,380 $ 292,985
One fiscal year before 311,709 270,785
Two fiscal years before 253,458 223,567
Three fiscal years before 209,844 409,856
Four fiscal years before 400,219 940,304
Prior 2,355,298 1,468,991
Total mortgage loans 3,594,908 3,606,488
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]    
Current fiscal year, writeoff 0 5
One fiscal year, writeoff 10 57
Two fiscal years, writeoff 21 94
Three fiscal years, writeoff 23 180
Four fiscal years, writeoff 40 107
Prior 35 280
Total writeoff 129 723
Less than or equal to 80%    
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]    
Current fiscal year 41,729 163,343
One fiscal year before 186,001 160,536
Two fiscal years before 154,811 149,624
Three fiscal years before 145,272 337,271
Four fiscal years before 335,701 922,745
Prior 2,337,464 1,465,398
Total mortgage loans 3,200,978 3,198,917
Greater than 80% and less than or equal to 90%    
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]    
Current fiscal year 9,440 57,484
One fiscal year before 58,384 63,333
Two fiscal years before 62,045 52,872
Three fiscal years before 47,307 53,845
Four fiscal years before 48,407 14,886
Prior 14,921 2,839
Total mortgage loans 240,504 245,259
Greater than 90% and less than or equal to 100%    
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]    
Current fiscal year 13,211 71,589
One fiscal year before 66,809 44,876
Two fiscal years before 34,812 18,732
Three fiscal years before 15,084 15,552
Four fiscal years before 13,056 2,193
Prior 2,384 539
Total mortgage loans 145,356 153,481
Greater than 100%    
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]    
Current fiscal year 0 569
One fiscal year before 515 2,040
Two fiscal years before 1,790 2,339
Three fiscal years before 2,181 3,188
Four fiscal years before 3,055 480
Prior 529 215
Total mortgage loans 8,070 8,831
20- and 30-year or more, amortizing fixed-rate    
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]    
Current fiscal year 57,525 270,116
One fiscal year before 286,937 261,486
Two fiscal years before 244,853 216,159
Three fiscal years before 202,896 378,287
Four fiscal years before 369,813 809,560
Prior 2,073,902 1,304,902
Total mortgage loans 3,235,926 3,240,510
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]    
Current fiscal year, writeoff 0 5
One fiscal year, writeoff 10 56
Two fiscal years, writeoff 21 92
Three fiscal years, writeoff 23 176
Four fiscal years, writeoff 39 106
Prior 33 242
Total writeoff 126 677
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 36,125 145,040
One fiscal year before 165,507 152,418
Two fiscal years before 147,187 142,942
Three fiscal years before 138,942 306,573
Four fiscal years before 306,059 792,049
Prior 2,056,187 1,301,401
Total mortgage loans 2,850,007 2,840,423
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 8,648 54,527
One fiscal year before 55,521 62,451
Two fiscal years before 61,284 52,313
Three fiscal years before 46,835 53,203
Four fiscal years before 47,842 14,848
Prior 14,851 2,790
Total mortgage loans 234,981 240,132
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 12,752 69,983
One fiscal year before 65,397 44,582
Two fiscal years before 34,598 18,590
Three fiscal years before 14,962 15,374
Four fiscal years before 12,904 2,184
Prior 2,355 517
Total mortgage loans 142,968 151,230
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 0 566
One fiscal year before 512 2,035
Two fiscal years before 1,784 2,314
Three fiscal years before 2,157 3,137
Four fiscal years before 3,008 479
Prior 509 194
Total mortgage loans 7,970 8,725
15-year or less, amortizing fixed-rate    
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]    
Current fiscal year 4,520 15,837
One fiscal year before 16,820 7,324
Two fiscal years before 6,767 5,288
Three fiscal years before 4,939 26,837
Four fiscal years before 25,813 125,843
Prior 254,788 141,455
Total mortgage loans 313,647 322,584
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]    
Current fiscal year, writeoff 0 0
One fiscal year, writeoff 0 1
Two fiscal years, writeoff 0 1
Three fiscal years, writeoff 0 3
Four fiscal years, writeoff 1 1
Prior 1 3
Total writeoff 2 9
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 3,936 13,753
One fiscal year before 14,952 6,794
Two fiscal years before 6,362 5,149
Three fiscal years before 4,844 26,742
Four fiscal years before 25,749 125,837
Prior 254,785 141,455
Total mortgage loans 310,628 319,730
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 395 1,464
One fiscal year before 1,376 440
Two fiscal years before 349 127
Three fiscal years before 90 82
Four fiscal years before 55 6
Prior 3 0
Total mortgage loans 2,268 2,119
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 189 619
One fiscal year before 491 88
Two fiscal years before 55 11
Three fiscal years before 5 13
Four fiscal years before 9 0
Prior 0 0
Total mortgage loans 749 731
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 1
One fiscal year before 1 2
Two fiscal years before 1 1
Three fiscal years before 0 0
Four fiscal years before 0 0
Prior 0 0
Total mortgage loans 2 4
Adjustable-rate    
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]    
Current fiscal year 2,335 7,032
One fiscal year before 7,952 1,975
Two fiscal years before 1,838 2,120
Three fiscal years before 2,009 4,732
Four fiscal years before 4,593 4,901
Prior 12,293 7,846
Total mortgage loans 31,020 28,606
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]    
Current fiscal year, writeoff 0 0
One fiscal year, writeoff 0 0
Two fiscal years, writeoff 0 1
Three fiscal years, writeoff 0 1
Four fiscal years, writeoff 0 0
Prior 0 0
Total writeoff 0 2
Adjustable-rate | Less than or equal to 80%    
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]    
Current fiscal year 1,668 4,550
One fiscal year before 5,542 1,324
Two fiscal years before 1,262 1,533
Three fiscal years before 1,486 3,956
Four fiscal years before 3,893 4,859
Prior 12,256 7,841
Total mortgage loans 26,107 24,063
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 397 1,493
One fiscal year before 1,487 442
Two fiscal years before 412 432
Three fiscal years before 382 560
Four fiscal years before 510 32
Prior 27 4
Total mortgage loans 3,215 2,963
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 270 987
One fiscal year before 921 206
Two fiscal years before 159 131
Three fiscal years before 117 165
Four fiscal years before 143 9
Prior 9 1
Total mortgage loans 1,619 1,499
Adjustable-rate | Greater than 100%    
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]    
Current fiscal year 0 2
One fiscal year before 2 3
Two fiscal years before 5 24
Three fiscal years before 24 51
Four fiscal years before 47 1
Prior 1 0
Total mortgage loans 79 81
Other    
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]    
Current fiscal year 0 0
One fiscal year before 0 0
Two fiscal years before 0 0
Three fiscal years before 0 0
Four fiscal years before 0 0
Prior 14,315 14,788
Total mortgage loans 14,315 14,788
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]    
Current fiscal year, writeoff 0 0
One fiscal year, writeoff 0 0
Two fiscal years, writeoff 0 0
Three fiscal years, writeoff 0 0
Four fiscal years, writeoff 0 0
Prior 1 35
Total writeoff 1 35
Other | Less than or equal to 80%    
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]    
Current fiscal year 0 0
One fiscal year before 0 0
Two fiscal years before 0 0
Three fiscal years before 0 0
Four fiscal years before 0 0
Prior 14,236 14,701
Total mortgage loans 14,236 14,701
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
One fiscal year before 0 0
Two fiscal years before 0 0
Three fiscal years before 0 0
Four fiscal years before 0 0
Prior 40 45
Total mortgage loans 40 45
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
One fiscal year before 0 0
Two fiscal years before 0 0
Three fiscal years before 0 0
Four fiscal years before 0 0
Prior 20 21
Total mortgage loans 20 21
Other | Greater than 100%    
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]    
Current fiscal year 0 0
One fiscal year before 0 0
Two fiscal years before 0 0
Three fiscal years before 0 0
Four fiscal years before 0 0
Prior 19 21
Total mortgage loans 19 21
U.S Government    
Financing Receivable, before Allowance for Credit Loss, by Origination Year [Abstract]    
Total mortgage loans 2,700 2,800
Financing Receivable, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]    
Total writeoff $ 1 $ 6