v3.26.3
Mortgage Loans - Single-Family Loan Restructurings Involving Borrowers Experiencing Financial Difficulty (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
financing receivable, loan restructuring [Line Items]        
Amortized cost basis of SF HFI loans in trial period modification plans $ 3,800 $ 3,500 $ 3,800 $ 3,500
Single family        
financing receivable, loan restructuring [Line Items]        
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount $ 8,495 $ 8,019 $ 22,030 $ 22,106
Financing Receivable, Excluding Accrued Interest, Modified in Period, to Total Financing Receivables, Percentage 0.30% 0.30% 0.70% 0.70%
Amortized cost basis of loans in payment deferral plans $ 1,700 $ 2,000 $ 5,600 $ 6,800
20- and 30-year or more, amortizing fixed-rate        
financing receivable, loan restructuring [Line Items]        
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount $ 8,289 $ 7,783 $ 21,481 $ 21,455
Financing Receivable, Excluding Accrued Interest, Modified in Period, to Total Financing Receivables, Percentage 0.30% 0.30% 0.80% 0.80%
15-year or less, amortizing fixed-rate        
financing receivable, loan restructuring [Line Items]        
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount $ 153 $ 173 $ 416 $ 498
Financing Receivable, Excluding Accrued Interest, Modified in Period, to Total Financing Receivables, Percentage 0.10% 0.10% 0.20% 0.20%
Adjustable-rate and other        
financing receivable, loan restructuring [Line Items]        
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount $ 53 $ 63 $ 133 $ 153
Financing Receivable, Excluding Accrued Interest, Modified in Period, to Total Financing Receivables, Percentage 0.10% 0.20% 0.30% 0.50%
payment delay [Member] | Single family        
financing receivable, loan restructuring [Line Items]        
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount $ 5,813 $ 5,576 $ 14,617 $ 15,393
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 5,612 5,347 14,080 14,759
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 152 172 412 496
payment delay [Member] | Adjustable-rate and other        
financing receivable, loan restructuring [Line Items]        
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount 49 57 125 138
payment delay and interest rate reduction [Member] | Single family        
financing receivable, loan restructuring [Line Items]        
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount 1 0 1 0
payment delay and interest rate reduction [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 0 1 0
payment delay and interest rate reduction [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 and interest rate reduction [Member] | Adjustable-rate and other        
financing receivable, loan restructuring [Line Items]        
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount 0 0 0 0
payment delay and term extension [Member] | Single family        
financing receivable, loan restructuring [Line Items]        
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount 1,890 2,189 5,591 6,088
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 1,885 2,183 5,579 6,073
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 4 2
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 4 5 8 13
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 791 254 1,821 625
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 791 253 1,821 623
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