v3.26.3
Available-for-Sale Securities - Schedule Amortized Cost to Fair Value by Major Security Types and Other Income Activity from Grantor Trust (Details) - USD ($)
$ in Thousands
Sep. 30, 2026
Dec. 31, 2025
Debt Securities, Available-for-Sale [Line Items]    
Amortized Cost $ 12,937,180 $ 12,377,325
Hedging Basis Adjustments, Amortized Cost (820,769) (363,915)
Gross Unrealized Gains 824,256 422,978
Hedging Basis Adjustments, Gross Unrealized Gains 820,769 363,915
Gross Unrealized Losses (961,684) (454,458)
Fair Value 12,799,752 12,345,845
Housing and U.S. obligations    
Debt Securities, Available-for-Sale [Line Items]    
Amortized Cost 2,220,401 2,223,460
Gross Unrealized Gains 2,451 2,599
Gross Unrealized Losses (14,892) (1,264)
Fair Value 2,207,960 2,224,795
MBS AFS Before Hedging Adjustments    
Debt Securities, Available-for-Sale [Line Items]    
Amortized Cost 11,537,548 10,517,780
Gross Unrealized Gains 1,036 56,464
Gross Unrealized Losses (946,792) (453,194)
Fair Value 10,591,792 10,121,050
Total Floating    
Debt Securities, Available-for-Sale [Line Items]    
Amortized Cost 258,636 293,613
Gross Unrealized Gains 419 593
Gross Unrealized Losses (1,942) (1,402)
Fair Value 257,113 292,804
CMO    
Debt Securities, Available-for-Sale [Line Items]    
Amortized Cost 256,314 291,061
Gross Unrealized Gains 341 509
Gross Unrealized Losses (1,942) (1,402)
Fair Value 254,713 290,168
Pass-through    
Debt Securities, Available-for-Sale [Line Items]    
Amortized Cost 2,322 2,552
Gross Unrealized Gains 78 84
Gross Unrealized Losses 0 0
Fair Value 2,400 2,636
Asset-Backed Securities, Fixed    
Debt Securities, Available-for-Sale [Line Items]    
Amortized Cost 11,278,912 10,224,167
Gross Unrealized Gains 617 55,871
Gross Unrealized Losses (944,850) (451,792)
Fair Value 10,334,679 9,828,246
CMBS    
Debt Securities, Available-for-Sale [Line Items]    
Amortized Cost 11,278,912 10,224,167
Gross Unrealized Gains 617 55,871
Gross Unrealized Losses (944,850) (451,792)
Fair Value 10,334,679 9,828,246
Mortgage-backed securities    
Debt Securities, Available-for-Sale [Line Items]    
Amortized Cost 10,716,779 10,153,865
Gross Unrealized Gains 821,805 420,379
Gross Unrealized Losses (946,792) (453,194)
Fair Value $ 10,591,792 $ 10,121,050