Derivative Instruments - Schedule of Gains and Losses for Derivative Instruments Recognized in Investment Gains (Losses) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Derivative [Line Items]
Gains (losses) on derivative instruments	$ (1,630)	$ (861)	$ (6,580)	$ (11,355)
Exchange-traded futures
Derivative [Line Items]
Gains (losses) on derivative instruments	(871)	2,032	(2,450)	(2,600)
Currency forwards
Derivative [Line Items]
Gains (losses) on derivative instruments	(9)	68	355	(37)
Interest rate swaps
Derivative [Line Items]
Gains (losses) on derivative instruments	282	114	425	51
Credit default swaps
Derivative [Line Items]
Gains (losses) on derivative instruments	(91)	(2,013)	(920)	(4,241)
Total return swaps
Derivative [Line Items]
Gains (losses) on derivative instruments	(682)	(1,645)	(3,938)	(3,701)
Option swaps
Derivative [Line Items]
Gains (losses) on derivative instruments	$ (259)	$ 583	$ (52)	$ (827)