Derivative Instruments - Summary of Gains and Losses for Derivative Instruments Recognized in Investment Gains (Losses) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Derivative [Line Items]
Net gains on derivative instruments	$ 3,802	$ (12,776)
Exchange-traded futures
Derivative [Line Items]
Net gains on derivative instruments	2,154	258
Currency forwards
Derivative [Line Items]
Net gains on derivative instruments	1,841	(655)
Interest rate swaps
Derivative [Line Items]
Net gains on derivative instruments	(560)	(352)
Credit default swaps
Derivative [Line Items]
Net gains on derivative instruments	1,531	434
Total return swaps
Derivative [Line Items]
Net gains on derivative instruments	(2,735)	(11,417)
Option swaps
Derivative [Line Items]
Net gains on derivative instruments	$ 1,571	$ (1,044)