v3.26.3
Mortgage Loans - Financial Effects of Single-Family Loan Restructurings Involving Borrowers Experiencing Financial Difficulty (Details) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
20- and 30-year or more, amortizing fixed-rate        
financing receivable, loan restructuring [Line Items]        
Financing Receivable, Modified, Weighted-Average Interest Rate Decrease from Modification 0.90% 0.50% 0.80% 0.60%
Financing Receivable, Modified, Weighted-Average Term Increase from Modification 144 months 146 months 144 months 151 months
Weighted average payment deferral or principal forbearance $ 28 $ 27 $ 27 $ 23
15-year or less, amortizing fixed-rate        
financing receivable, loan restructuring [Line Items]        
Financing Receivable, Modified, Weighted-Average Interest Rate Decrease from Modification 0.00%   0.00%  
Financing Receivable, Modified, Weighted-Average Term Increase from Modification 36 months 39 months 36 months 38 months
Weighted average payment deferral or principal forbearance $ 10 $ 11 $ 11 $ 11
Adjustable-rate and other        
financing receivable, loan restructuring [Line Items]        
Financing Receivable, Modified, Weighted-Average Interest Rate Decrease from Modification   0.90%   0.80%
Financing Receivable, Modified, Weighted-Average Term Increase from Modification 105 months 165 months 112 months 166 months
Weighted average payment deferral or principal forbearance $ 14 $ 18 $ 16 $ 15