Derivative Instruments - Notional Value and Fair Value of Derivative Instruments (Details) - Not Designated as Hedging Instrument - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Derivative [Line Items]
Notional Value	$ 529,939	$ 480,991
Derivative Assets	37,348	15,422
Derivative Liabilities	11,758	16,923
Exchange-traded futures
Derivative [Line Items]
Notional Value	150,594	131,876
Derivative Assets	8,053	392
Derivative Liabilities	0	1,186
Currency forwards
Derivative [Line Items]
Notional Value	45,300	66,058
Derivative Assets	4,876	7,344
Derivative Liabilities	5,162	6,980
Interest rate swaps
Derivative [Line Items]
Notional Value	18,727	13,483
Derivative Assets	430	497
Derivative Liabilities	372	833
Credit default swaps
Derivative [Line Items]
Notional Value	215,931	155,757
Derivative Assets	19,699	6,594
Derivative Liabilities	6,052	6,967
Total return swaps
Derivative [Line Items]
Notional Value	49,387	63,817
Derivative Assets	4,290	595
Derivative Liabilities	0	527
Option swaps
Derivative [Line Items]
Notional Value	50,000	50,000
Derivative Assets	0	0
Derivative Liabilities	$ 172	$ 430