Derivatives and Hedging Activities - Schedule of Derivative Instruments (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2026 USD ($)
Interest rate swaps
Changes in notional amount of derivative instruments [Roll Forward]
Notional amount, beginning balance	$ 3,820,000
Additions	1,875,000
Settlement, Termination, Expiration or Exercise	(930,000)
Notional amount, ending balance	4,765,000
U.S. Treasury futures contracts
Changes in notional amount of derivative instruments [Roll Forward]
Notional amount, beginning balance	1,090,000
Additions	2,720,000
Settlement, Termination, Expiration or Exercise	(2,530,000)
Notional amount, ending balance	1,280,000
TBA purchase contracts
Changes in notional amount of derivative instruments [Roll Forward]
Notional amount, beginning balance	0
Additions	12,975,000
Settlement, Termination, Expiration or Exercise	(11,375,000)
Notional amount, ending balance	1,600,000
TBA sale contracts
Changes in notional amount of derivative instruments [Roll Forward]
Notional amount, beginning balance	0
Additions	(11,775,000)
Settlement, Termination, Expiration or Exercise	11,375,000
Notional amount, ending balance	$ (400,000)