v3.26.1
Concentration of Credit and Other Risks - Concentration of Credit Risk - Single-Family Mortgage Portfolio (Details)
$ in Millions
Mar. 31, 2026
USD ($)
Concentration Risk [Line Items]  
Single-Family serious delinquency rate 0.60%
West  
Concentration Risk [Line Items]  
Single-Family serious delinquency rate 0.47%
Northeast  
Concentration Risk [Line Items]  
Single-Family serious delinquency rate 0.63%
Southeast  
Concentration Risk [Line Items]  
Single-Family serious delinquency rate 0.68%
Southwest  
Concentration Risk [Line Items]  
Single-Family serious delinquency rate 0.65%
North Central  
Concentration Risk [Line Items]  
Single-Family serious delinquency rate 0.59%
California  
Concentration Risk [Line Items]  
Single-Family serious delinquency rate 0.46%
Texas  
Concentration Risk [Line Items]  
Single-Family serious delinquency rate 0.74%
Florida  
Concentration Risk [Line Items]  
Single-Family serious delinquency rate 0.81%
New York  
Concentration Risk [Line Items]  
Single-Family serious delinquency rate 0.82%
Illinois  
Concentration Risk [Line Items]  
Single-Family serious delinquency rate 0.71%
All Other  
Concentration Risk [Line Items]  
Single-Family serious delinquency rate 0.56%
Geographic Concentration Risk | All Other  
Concentration Risk [Line Items]  
Portfolio UPB $ 1,949,629
Concentration risk percentage 62.00%
Geographic Concentration Risk | Single-family UPB  
Concentration Risk [Line Items]  
Portfolio UPB $ 3,157,676
Concentration risk percentage 100.00%
Geographic Concentration Risk | Single-family UPB | West  
Concentration Risk [Line Items]  
Portfolio UPB $ 919,994
Concentration risk percentage 29.00%
Geographic Concentration Risk | Single-family UPB | Northeast  
Concentration Risk [Line Items]  
Portfolio UPB $ 729,486
Concentration risk percentage 23.00%
Geographic Concentration Risk | Single-family UPB | Southeast  
Concentration Risk [Line Items]  
Portfolio UPB $ 565,501
Concentration risk percentage 18.00%
Geographic Concentration Risk | Single-family UPB | Southwest  
Concentration Risk [Line Items]  
Portfolio UPB $ 479,012
Concentration risk percentage 15.00%
Geographic Concentration Risk | Single-family UPB | North Central  
Concentration Risk [Line Items]  
Portfolio UPB $ 463,683
Concentration risk percentage 15.00%
Geographic Concentration Risk | Single-family UPB | California  
Concentration Risk [Line Items]  
Portfolio UPB $ 507,586
Concentration risk percentage 16.00%
Geographic Concentration Risk | Single-family UPB | Texas  
Concentration Risk [Line Items]  
Portfolio UPB $ 229,802
Concentration risk percentage 7.00%
Geographic Concentration Risk | Single-family UPB | Florida  
Concentration Risk [Line Items]  
Portfolio UPB $ 213,829
Concentration risk percentage 7.00%
Geographic Concentration Risk | Single-family UPB | New York  
Concentration Risk [Line Items]  
Portfolio UPB $ 138,886
Concentration risk percentage 4.00%
Geographic Concentration Risk | Single-family UPB | Illinois  
Concentration Risk [Line Items]  
Portfolio UPB $ 117,944
Concentration risk percentage 4.00%