v3.26.3
Investments in Securities - Additional Information (Details) - USD ($)
$ in Thousands
Sep. 30, 2026
Dec. 31, 2025
Debt Securities, Available-for-sale [Line Items]    
Debt securities $ 20,465,892 $ 20,015,749
Trading securities 20,465,892 20,015,749
To-be-Announced Agency Securities    
Debt Securities, Available-for-sale [Line Items]    
Derivative assets (liabilities), net (24,401) 0
Total TBA Agency Securities    
Debt Securities, Available-for-sale [Line Items]    
Trading securities $ 804,760 $ 0