Derivative Instruments - Summary of Gains and Losses for Derivative Instruments Recognized in Investment Gains (Losses) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Derivative [Line Items]
Net (losses) on derivative instruments	$ (13,522)	$ (11,074)	$ (9,720)	$ (23,850)
Exchange-traded futures
Derivative [Line Items]
Net (losses) on derivative instruments	(8,403)	(3,891)	(6,249)	(3,633)
Currency forwards
Derivative [Line Items]
Net (losses) on derivative instruments	1,786	(5,120)	3,627	(5,775)
Interest rate swaps
Derivative [Line Items]
Net (losses) on derivative instruments	46	42	(514)	(310)
Credit default swaps
Derivative [Line Items]
Net (losses) on derivative instruments	(3,525)	(2,921)	(1,994)	(2,487)
Total return swaps
Derivative [Line Items]
Net (losses) on derivative instruments	(3,480)	2,040	(6,215)	(9,377)
Option swaps
Derivative [Line Items]
Net (losses) on derivative instruments	$ 54	$ (1,224)	$ 1,625	$ (2,268)