Mortgage Loans - Aging (Details) - USD ($) $ in Millions	6 Months Ended
Jun. 30, 2026	Dec. 31, 2025
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	$ 4,133,172	$ 4,133,279
Loans 90 Days or More Delinquent and Accruing Interest	120	209
Nonaccrual Loans with No Allowance	$ 6,316	6,041
Table Footnote [Abstract]
Serious delinquency, days past due	90 days
Total Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	$ 72,644	71,985
30 - 59 Days Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	38,139	36,206
60 - 89 Days Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	9,593	10,685
Seriously Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	24,912	25,094
Current
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	4,060,528	4,061,294
Single-family
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	3,599,610	3,609,326
Loans 90 Days or More Delinquent and Accruing Interest	119	191
Nonaccrual Loans with No Allowance	4,344	4,056
Table Footnote [Abstract]
Mortgage loans in process of foreclosure	$ 6,000	5,400
Single-family \| Minimum
Table Footnote [Abstract]
Serious delinquency, days past due	90 days
Single-family \| Total Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	$ 69,441	68,226
Single-family \| 30 - 59 Days Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	37,502	35,687
Single-family \| 60 - 89 Days Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	9,593	10,685
Single-family \| Seriously Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	22,346	21,854
Single-family \| Current
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	3,530,169	3,541,100
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	3,243,830	3,240,510
Loans 90 Days or More Delinquent and Accruing Interest	105	171
Nonaccrual Loans with No Allowance	3,961	3,713
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	66,079	64,826
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	35,520	33,764
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	9,172	10,205
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	21,387	20,857
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	3,177,751	3,175,684
Single-family \| 15-year or less, amortizing fixed-rate
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	304,889	322,584
Loans 90 Days or More Delinquent and Accruing Interest	4	7
Nonaccrual Loans with No Allowance	241	193
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	2,193	2,170
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	1,379	1,313
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	276	310
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	538	547
Single-family \| 15-year or less, amortizing fixed-rate \| Current
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	302,696	320,414
Single-family \| Adjustable-rate
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	34,498	28,606
Loans 90 Days or More Delinquent and Accruing Interest	0	1
Nonaccrual Loans with No Allowance	17	17
Single-family \| Adjustable-rate \| Total Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	302	294
Single-family \| Adjustable-rate \| 30 - 59 Days Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	177	155
Single-family \| Adjustable-rate \| 60 - 89 Days Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	38	43
Single-family \| Adjustable-rate \| Seriously Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	87	96
Single-family \| Adjustable-rate \| Current
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	34,196	28,312
Single-family \| Other
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	16,393	17,626
Loans 90 Days or More Delinquent and Accruing Interest	10	12
Nonaccrual Loans with No Allowance	125	133
Single-family \| Other \| Total Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	867	936
Single-family \| Other \| 30 - 59 Days Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	426	455
Single-family \| Other \| 60 - 89 Days Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	107	127
Single-family \| Other \| Seriously Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	334	354
Single-family \| Other \| Current
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	15,526	16,690
Multifamily
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	533,562	523,953
Loans 90 Days or More Delinquent and Accruing Interest	1	18
Nonaccrual Loans with No Allowance	$ 1,972	1,985
Multifamily \| Minimum
Table Footnote [Abstract]
Serious delinquency, days past due	60 days
Multifamily \| Maximum
Table Footnote [Abstract]
Serious delinquency, days past due	89 days
Multifamily \| Total Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	$ 3,203	3,759
Multifamily \| 30 - 59 Days Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	637	519
Multifamily \| Seriously Delinquent
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	2,566	3,240
Multifamily \| Current
Financing Receivable, Past Due [Line Items]
Loans held for investment, excluding fair value option	$ 530,359	$ 520,194

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

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Amortized cost of financing receivable on nonaccrual status with no allowance for credit loss. Excludes net investment in lease.

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