v3.26.3
Available-for-Sale Securities - Schedule of Interest Rate Payment Terms of Investments in Mortgage-backed Securities and State And Local Housing Finance Agency Obligations Classified as AFS Securities (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
Fair Value 12,799,752 12,345,845
Mortgage-backed securities    
Debt Securities, Available-for-Sale [Line Items]    
Amortized Cost 10,716,779 10,153,865
Fair Value 10,591,792 10,121,050
Total Floating    
Debt Securities, Available-for-Sale [Line Items]    
Amortized Cost 258,636 293,613
Fair Value 257,113 292,804
CMO    
Debt Securities, Available-for-Sale [Line Items]    
Amortized Cost 256,314 291,061
Fair Value 254,713 290,168
Pass-through    
Debt Securities, Available-for-Sale [Line Items]    
Amortized Cost 2,322 2,552
Fair Value 2,400 2,636
Total Fixed    
Debt Securities, Available-for-Sale [Line Items]    
Amortized Cost 10,458,143 9,860,252
Fair Value 10,334,679 9,828,246
CMBS    
Debt Securities, Available-for-Sale [Line Items]    
Amortized Cost 10,458,143 9,860,252
Fair Value 10,334,679 9,828,246
Housing and U.S. Obligations, Floating    
Debt Securities, Available-for-Sale [Line Items]    
Amortized Cost 1,664,730 1,665,775
Fair Value 1,667,158 1,664,523
Housing and U.S. Obligations, Fixed    
Debt Securities, Available-for-Sale [Line Items]    
Amortized Cost 555,671 557,685
Fair Value $ 540,802 $ 560,272