Derivative Instruments - Activity of Derivative Instruments Not Designated as Hedges (Details) - Trading - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Interest rate caps
Derivative Instruments and Hedging Activities Disclosures [Roll Forward]
Beginning balance	$ 45,142	$ 550,025
Additions/Transfers In	45,142	177,044
Terminations/Transfers Out	(45,142)	(681,927)
Ending balance	45,142	45,142
Options
Derivative Instruments and Hedging Activities Disclosures [Roll Forward]
Beginning balance	0	0
Additions/Transfers In	741	382
Terminations/Transfers Out	(741)	(382)
Ending balance	0	0
TBAs
Derivative Instruments and Hedging Activities Disclosures [Roll Forward]
Beginning balance	0
Additions/Transfers In	170,000
Terminations/Transfers Out	(170,000)
Ending balance	0	0
Interest rate swaps
Derivative Instruments and Hedging Activities Disclosures [Roll Forward]
Beginning balance	4,134,267	2,778,015
Additions/Transfers In	3,584,491	3,063,163
Terminations/Transfers Out	(2,799,360)	(1,706,911)
Ending balance	4,919,398	4,134,267
Credit default swaps
Derivative Instruments and Hedging Activities Disclosures [Roll Forward]
Beginning balance	400,000	0
Additions/Transfers In	75,000	400,000
Terminations/Transfers Out	0	0
Ending balance	475,000	400,000
U.S. Treasury futures
Derivative Instruments and Hedging Activities Disclosures [Roll Forward]
Beginning balance	406,100	0
Additions/Transfers In	2,576,800	905,050
Terminations/Transfers Out	(2,081,700)	(498,950)
Ending balance	901,200	406,100
Commodity futures
Derivative Instruments and Hedging Activities Disclosures [Roll Forward]
Beginning balance	0
Additions/Transfers In	299,736
Terminations/Transfers Out	(100,060)
Ending balance	$ 199,676	$ 0