Mortgage Loans - Aging Analysis (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2025	Dec. 31, 2024
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	$ 4,133,279	$ 4,152,406
Loans 90 Days or More Delinquent and Accruing Interest	209	445
Nonaccrual Loans with No Allowance(2)	$ 6,041	5,270
Table Footnote
Serious delinquency: days past due	90 days
Total Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	$ 71,985	70,322
30-59 Days Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	36,206	37,021
60 - 89 Days Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	10,685	10,122
Seriously Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	25,094	23,179
Current
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	4,061,294	4,082,084
Single-family
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	3,609,326	3,662,679
Loans 90 Days or More Delinquent and Accruing Interest	191	369
Nonaccrual Loans with No Allowance(2)	4,056	4,200
Table Footnote
Mortgage loans in process of foreclosure	$ 5,400	$ 4,700
Single-family \| Minimum
Table Footnote
Serious delinquency: days past due	90 days	90 days
Single-family \| Total Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	$ 68,226	$ 67,771
Single-family \| 30-59 Days Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	35,687	36,530
Single-family \| 60 - 89 Days Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	10,685	10,122
Single-family \| Seriously Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	21,854	21,119
Single-family \| Current
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	3,541,100	3,594,908
Single-family \| 20- and 30-year or more, amortizing fixed-rate
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	3,240,510	3,247,328
Loans 90 Days or More Delinquent and Accruing Interest	171	329
Nonaccrual Loans with No Allowance(2)	3,713	3,790
Single-family \| 20- and 30-year or more, amortizing fixed-rate \| Total Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	64,826	63,925
Single-family \| 20- and 30-year or more, amortizing fixed-rate \| 30-59 Days Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	33,764	34,339
Single-family \| 20- and 30-year or more, amortizing fixed-rate \| 60 - 89 Days Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	10,205	9,582
Single-family \| 20- and 30-year or more, amortizing fixed-rate \| Seriously Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	20,857	20,004
Single-family \| 20- and 30-year or more, amortizing fixed-rate \| Current
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	3,175,684	3,183,403
Single-family \| 15-year or less, amortizing fixed-rate
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	322,584	369,727
Loans 90 Days or More Delinquent and Accruing Interest	7	16
Nonaccrual Loans with No Allowance(2)	193	208
Single-family \| 15-year or less, amortizing fixed-rate \| Total Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	2,170	2,513
Single-family \| 15-year or less, amortizing fixed-rate \| 30-59 Days Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	1,313	1,545
Single-family \| 15-year or less, amortizing fixed-rate \| 60 - 89 Days Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	310	352
Single-family \| 15-year or less, amortizing fixed-rate \| Seriously Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	547	616
Single-family \| 15-year or less, amortizing fixed-rate \| Current
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	320,414	367,214
Single-family \| Adjustable-rate
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	28,606	25,018
Loans 90 Days or More Delinquent and Accruing Interest	1	3
Nonaccrual Loans with No Allowance(2)	17	18
Single-family \| Adjustable-rate \| Total Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	294	295
Single-family \| Adjustable-rate \| 30-59 Days Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	155	158
Single-family \| Adjustable-rate \| 60 - 89 Days Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	43	45
Single-family \| Adjustable-rate \| Seriously Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	96	92
Single-family \| Adjustable-rate \| Current
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	28,312	24,723
Single-family \| Other
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	17,626	20,606
Loans 90 Days or More Delinquent and Accruing Interest	12	21
Nonaccrual Loans with No Allowance(2)	133	184
Single-family \| Other \| Total Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	936	1,038
Single-family \| Other \| 30-59 Days Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	455	488
Single-family \| Other \| 60 - 89 Days Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	127	143
Single-family \| Other \| Seriously Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	354	407
Single-family \| Other \| Current
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	16,690	19,568
Multifamily
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	523,953	489,727
Loans 90 Days or More Delinquent and Accruing Interest	18	76
Nonaccrual Loans with No Allowance(2)	$ 1,985	$ 1,070
Multifamily \| Minimum
Table Footnote
Serious delinquency: days past due	60 days	60 days
Multifamily \| Maximum
Table Footnote
Serious delinquency: days past due	89 days	89 days
Multifamily \| Total Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	$ 3,759	$ 2,551
Multifamily \| 30-59 Days Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	519	491
Multifamily \| Seriously Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	3,240	2,060
Multifamily \| Current
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	$ 520,194	$ 487,176

Financing Receivable, Excluding Fair Value Option, before Allowance for Credit Loss

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