v3.26.1
Mortgage Loans - Single-Family Loan Restructurings Involving Borrowers Experiencing Financial Difficulty (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
financing receivable, loan restructuring [Line Items]        
Amortized cost basis of SF HFI loans in trial period modification plans $ 4,200 $ 3,200 $ 4,200 $ 3,200
Single family        
financing receivable, loan restructuring [Line Items]        
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount $ 8,152 $ 8,371 $ 15,648 $ 16,400
Financing Receivable, Excluding Accrued Interest, Modified in Period, to Total Financing Receivables, Percentage 0.30% 0.30% 0.50% 0.50%
Amortized cost basis of loans in payment deferral plans $ 1,800 $ 2,200 $ 4,000 $ 4,900
20- and 30-year or more, amortizing fixed-rate        
financing receivable, loan restructuring [Line Items]        
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount $ 7,942 $ 8,137 $ 15,233 $ 15,898
Financing Receivable, Excluding Accrued Interest, Modified in Period, to Total Financing Receivables, Percentage 0.30% 0.30% 0.50% 0.60%
15-year or less, amortizing fixed-rate        
financing receivable, loan restructuring [Line Items]        
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount $ 163 $ 178 $ 321 $ 391
Financing Receivable, Excluding Accrued Interest, Modified in Period, to Total Financing Receivables, Percentage 0.10% 0.10% 0.10% 0.10%
Adjustable-rate and other        
financing receivable, loan restructuring [Line Items]        
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount $ 47 $ 56 $ 94 $ 111
Financing Receivable, Excluding Accrued Interest, Modified in Period, to Total Financing Receivables, Percentage 0.10% 0.20% 0.30% 0.40%
payment delay [Member] | Single family        
financing receivable, loan restructuring [Line Items]        
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount $ 5,573 $ 5,741 $ 10,845 $ 12,035
payment delay [Member] | 20- and 30-year or more, amortizing fixed-rate        
financing receivable, loan restructuring [Line Items]        
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount 5,366 5,515 10,436 11,545
payment delay [Member] | 15-year or less, amortizing fixed-rate        
financing receivable, loan restructuring [Line Items]        
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount 162 177 319 390
payment delay [Member] | Adjustable-rate and other        
financing receivable, loan restructuring [Line Items]        
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount 45 49 90 100
payment delay and term extension [Member] | Single family        
financing receivable, loan restructuring [Line Items]        
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount 1,905 2,365 3,749 3,979
payment delay and term extension [Member] | 20- and 30-year or more, amortizing fixed-rate        
financing receivable, loan restructuring [Line Items]        
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount 1,902 2,358 3,743 3,969
payment delay and term extension [Member] | 15-year or less, amortizing fixed-rate        
financing receivable, loan restructuring [Line Items]        
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount 1 1 2 1
payment delay and term extension [Member] | Adjustable-rate and other        
financing receivable, loan restructuring [Line Items]        
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount 2 6 4 9
payment delay, interest rate reduction, and term extension [Member] | Single family        
financing receivable, loan restructuring [Line Items]        
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount 674 265 1,054 386
payment delay, interest rate reduction, and term extension [Member] | 20- and 30-year or more, amortizing fixed-rate        
financing receivable, loan restructuring [Line Items]        
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount 674 264 1,054 384
payment delay, interest rate reduction, and term extension [Member] | 15-year or less, amortizing fixed-rate        
financing receivable, loan restructuring [Line Items]        
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount 0 0 0 0
payment delay, interest rate reduction, and term extension [Member] | Adjustable-rate and other        
financing receivable, loan restructuring [Line Items]        
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount $ 0 $ 1 $ 0 $ 2