v3.26.1
Mortgage Loans - Single-Family Loan Restructurings Involving Borrowers Experiencing Financial Difficulty (Details) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
financing receivable, loan restructuring [Line Items]    
Amortized cost basis of SF HFI loans in trial period modification plans $ 4,100 $ 2,900
Single family    
financing receivable, loan restructuring [Line Items]    
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount $ 8,631 $ 9,431
Financing Receivable, Excluding Accrued Interest, Modified in Period, to Total Financing Receivables, Percentage 0.30% 0.30%
Amortized cost basis of loans in payment deferral plans $ 2,300 $ 2,800
20- and 30-year or more, amortizing fixed-rate    
financing receivable, loan restructuring [Line Items]    
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount $ 8,384 $ 9,104
Financing Receivable, Excluding Accrued Interest, Modified in Period, to Total Financing Receivables, Percentage 0.30% 0.30%
15-year or less, amortizing fixed-rate    
financing receivable, loan restructuring [Line Items]    
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount $ 191 $ 255
Financing Receivable, Excluding Accrued Interest, Modified in Period, to Total Financing Receivables, Percentage 0.10% 0.10%
Adjustable-rate and other    
financing receivable, loan restructuring [Line Items]    
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount $ 56 $ 72
Financing Receivable, Excluding Accrued Interest, Modified in Period, to Total Financing Receivables, Percentage 0.20% 0.30%
payment delay [Member] | Single family    
financing receivable, loan restructuring [Line Items]    
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount $ 6,322 $ 7,630
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 6,079 7,308
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 189 255
payment delay [Member] | Adjustable-rate and other    
financing receivable, loan restructuring [Line Items]    
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount 54 67
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 1,679
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 1,886 1,675
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 2 0
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 4
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 419 122
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 419 121
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
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