Derivatives - Schedule of Interest Rate Hedging Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2025	Dec. 31, 2024
Derivative [Line Items]
Margin deposit assets	$ 315,000	$ 219,000
Interest rate swaps | Short position | Not Designated as Hedging Instrument, Economic Hedge
Derivative [Line Items]
Notional balance	$ (7,160,000)	$ (5,385,000)
Derivative, average fixed interest rate	3.70%	3.61%
Interest rate swaps | Short position | Not Designated as Hedging Instrument, Economic Hedge | 4-5 years
Derivative [Line Items]
Notional balance	$ (1,275,000)	$ (1,275,000)
Derivative, average fixed interest rate	3.42%	3.42%
Interest rate swaps | Short position | Not Designated as Hedging Instrument, Economic Hedge | 5-6 years
Derivative [Line Items]
Notional balance	$ (10,000)
Derivative, average fixed interest rate	4.15%
Interest rate swaps | Short position | Not Designated as Hedging Instrument, Economic Hedge | 6-7 years
Derivative [Line Items]
Notional balance	$ (3,750,000)	$ (3,085,000)
Derivative, average fixed interest rate	3.67%	3.61%
Interest rate swaps | Short position | Not Designated as Hedging Instrument, Economic Hedge | 9-10 years
Derivative [Line Items]
Notional balance	$ (1,875,000)	$ (1,025,000)
Derivative, average fixed interest rate	3.93%	3.83%
Interest rate swaps | Short position | Not Designated as Hedging Instrument, Economic Hedge | 10-15 years
Derivative [Line Items]
Notional balance	$ (250,000)
Derivative, average fixed interest rate	3.73%
U.S. Treasury futures | Short position | 30-year | Not Designated as Hedging Instrument, Economic Hedge
Derivative [Line Items]
Notional balance	$ (953,500)	$ (516,500)
U.S. Treasury futures | Short position | 10-year | Not Designated as Hedging Instrument, Economic Hedge
Derivative [Line Items]
Notional balance	(1,521,500)	(735,000)
U.S. Treasury futures | Short position | Not Designated as Hedging Instrument, Economic Hedge
Derivative [Line Items]
Notional balance	$ (2,475,000)	$ (1,251,500)