Derivatives - Schedule of Interest Rate Hedging Instruments (Details) - USD ($)	Sep. 30, 2024	Dec. 31, 2023
Derivative [Line Items]
Derivative assets	$ 4,138,000	$ 54,361,000
Derivative liabilities	3,662,000	0
U.S. Treasury futures
Derivative [Line Items]
Derivative assets	5,600,000
Derivative Instruments Not Designated as Hedging Instruments, at Carrying Value	0
Derivative liabilities		219,900,000
U.S. Treasury futures | Short position | Not Designated as Hedging Instrument, Economic Hedge
Derivative [Line Items]
Notional balance	(4,355,000,000)	(4,880,000,000)
Interest rate swaps
Derivative [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, at Carrying Value	0
Derivative liabilities	10,200,000	0
Interest rate swaps | Short position | Not Designated as Hedging Instrument, Economic Hedge
Derivative [Line Items]
Notional balance	$ (1,535,000,000)	$ 0
Derivative, Average Fixed Interest Rate	3.46%
Interest rate swaps | Short position | Not Designated as Hedging Instrument, Economic Hedge | Less than 5 years
Derivative [Line Items]
Notional balance	$ (1,275,000,000)
Derivative, Average Fixed Interest Rate	3.42%
Interest rate swaps | Short position | Not Designated as Hedging Instrument, Economic Hedge | Less than 7 years
Derivative [Line Items]
Notional balance	$ (260,000,000)
Derivative, Average Fixed Interest Rate	3.63%