v3.26.1
Investments - AFS Securities - Major Security Types (Details) - USD ($)
$ in Thousands
Jun. 30, 2026
Dec. 31, 2025
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost - AFS [1] $ 15,546,015 $ 15,251,368
Gross Unrealized Gains 100,755 74,396
Gross Unrealized Losses (3,852) (6,719)
Estimated Fair Value 15,642,918 15,319,045
Unamortized premium (discount) (111,209) (129,980)
Applicable fair value hedging-basis adjustment (568,877) (406,176)
Accrued interest receivable $ 74,179 $ 69,614
Debt Securities, Available-for-Sale, Excluded Accrued Interest from Amortized Cost [true false] true true
Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration] Accrued interest receivable Accrued interest receivable
U.S. Treasury obligations    
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost - AFS $ 6,422,162 $ 5,987,156
Gross Unrealized Gains 17,369 21,148
Gross Unrealized Losses 0 0
Estimated Fair Value 6,439,531 6,008,304
GSE and TVA debentures    
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost - AFS 949,552 1,466,126
Gross Unrealized Gains 4,842 8,094
Gross Unrealized Losses 0 0
Estimated Fair Value 954,394 1,474,220
GSE multifamily MBS | Multifamily    
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost - AFS 8,174,301 7,798,086
Gross Unrealized Gains 78,544 45,154
Gross Unrealized Losses (3,852) (6,719)
Estimated Fair Value $ 8,248,993 $ 7,836,521
[1] At June 30, 2026 and December 31, 2025, includes net unamortized discounts of $(111,209) and $(129,980), respectively, and fair-value hedging basis adjustments of $(568,877) and $(406,176), respectively. Excludes accrued interest receivable at June 30, 2026 and December 31, 2025 of $74,179 and $69,614, respectively.