v3.26.1
Mortgage Loans Held for Portfolio - By Term (Details) - USD ($)
$ in Thousands
 6 Months Ended
Jun. 30, 2026
Dec. 31, 2025
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Total mortgage loans held for portfolio, net2 $ 13,035,549 $ 12,443,814
Fixed-rate long-term mortgages    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Total mortgage loans held for portfolio, UPB 12,246,837 11,629,354
Fixed-rate medium-term1 mortgages    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Total mortgage loans held for portfolio, UPB [1] $ 544,805 578,035
Fixed-rate medium-term1 mortgages | Maximum    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Origination term 15 years  
Residential Portfolio Segment    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Total mortgage loans held for portfolio, UPB $ 12,791,642 12,207,389
Unamortized premiums 262,677 254,899
Unamortized discounts (15,663) (15,779)
Hedging basis adjustments, net (3,007) (2,570)
Total mortgage loans held for portfolio 13,035,649 12,443,939
Allowance for credit losses (100) (125)
Total mortgage loans held for portfolio, net2 [2] 13,035,549 12,443,814
Accrued interest $ 84,437 $ 80,370
Financing Receivable, Practical Expedient, Accrued Interest Exclusion [true false] true true
Financing Receivable, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration] Accrued interest receivable Accrued interest receivable
[1] Defined as a term of 15 years or less at origination.
[2] Excludes accrued interest receivable at June 30, 2026 and December 31, 2025 of $84,437 and $80,370, respectively.