Derivative Instruments - Narrative (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024 USD ($) swap	Sep. 30, 2023 USD ($) swap	Sep. 30, 2024 USD ($) contract swap	Sep. 30, 2023 USD ($) contract swap	Dec. 31, 2023 USD ($)
Derivative [Line Items]
Realized gains (losses) on derivatives	$ (4,864)	$ 0	$ (22,181)	$ (40,957)
Notional amount	2,000,000		2,000,000		$ 2,500,000
Future
Derivative [Line Items]
Realized gains (losses) on derivatives	(4,864)	0	(4,864)	(6,344)
Future | 5 Year U.S. Treasury Future, Number One
Derivative [Line Items]
Notional amount	139,000		$ 139,000
Derivative contracts entered into during period | contract			1,391
Length of contract			5 years
Future | 5 Year U.S. Treasury Future, Number Two
Derivative [Line Items]
Notional amount	$ 168,000		$ 168,000
Derivative contracts entered into during period | contract			1,684
Length of contract			5 years
Future | 5 Year U.S. Treasury Future
Derivative [Line Items]
Notional amount		600,000		$ 600,000
Derivative contracts entered into during period | contract				6,000
Length of contract				5 years
Future | 2 Year U.S. Treasury Future
Derivative [Line Items]
Notional amount		$ 375,000		$ 375,000
Derivative contracts entered into during period | contract				1,875
Length of contract				2 years
Interest Rate Swaps
Derivative [Line Items]
Derivative weighted average pay rate	3.56%		3.56%		3.26%
Derivative weighted average receive rate	4.96%		4.96%		5.40%
Derivative remaining maturity	1 year		1 year		1 year
Number of derivative contracts terminated | swap	0	0
Realized gains (losses) on derivatives	$ 0	$ 0	$ (17,317)	$ (45,226)
Derivative, contracts matured during period | swap			1
Payments to terminate derivatives				45,000
Derivative, notional amount of derivative terminated				$ 2,500,000
Notional amount	$ 1,500,000		$ 1,500,000		$ 1,000,000
Derivative contracts entered into during period | contract			3
Length of contract			1 year
Derivative interest rate	3.56%		3.56%
Interest Rate Swaps | Nine Months Ended
Derivative [Line Items]
Notional amount	$ 500,000		$ 500,000
Swaptions
Derivative [Line Items]
Number of derivative contracts terminated | contract				3
Realized gains (losses) on derivatives	0	0	$ 0	$ 10,613
Derivative, notional amount of derivative terminated				2,300,000
Derivative contracts exercised | contract			3
Notional amount	500,000	$ 1,000,000	$ 500,000	$ 1,000,000	$ 1,500,000
Derivative contracts entered into during period | swap				3
Length of contract				1 year
Derivative interest rate		3.56%		3.56%
Strike rate		3.56%		3.56%
Swaptions | Nine Months Ended
Derivative [Line Items]
Notional amount	$ 500,000		$ 500,000
Swaptions | Three Swaptions, 3 years, 3.56% strike rate
Derivative [Line Items]
Notional amount		$ 1,500,000		$ 1,500,000
Options on Treasury futures
Derivative [Line Items]
Realized gains (losses) on derivatives				$ (187)
Derivative contracts entered into during period | contract				400
Options on Treasury futures | 5 Year U.S. Treasury Future
Derivative [Line Items]
Length of contract				5 years
Options on Treasury futures | 2 Year U.S. Treasury Future
Derivative [Line Items]
Length of contract				2 years