Derivative Instruments - Notional Value and Fair Value of Derivative Instruments (Details) - Not Designated as Hedging Instrument - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Derivative [Line Items]
Notional Value	$ 459,964	$ 480,991
Derivative Assets	27,347	15,422
Derivative Liabilities	12,524	16,923
Exchange-traded futures
Derivative [Line Items]
Notional Value	116,242	131,876
Derivative Assets	1,724	392
Derivative Liabilities	348	1,186
Currency forwards
Derivative [Line Items]
Notional Value	46,780	66,058
Derivative Assets	5,507	7,344
Derivative Liabilities	5,283	6,980
Interest rate swaps
Derivative [Line Items]
Notional Value	10,683	13,483
Derivative Assets	20	497
Derivative Liabilities	87	833
Credit default swaps
Derivative [Line Items]
Notional Value	181,219	155,757
Derivative Assets	17,269	6,594
Derivative Liabilities	6,586	6,967
Total return swaps
Derivative [Line Items]
Notional Value	55,040	63,817
Derivative Assets	2,827	595
Derivative Liabilities	178	527
Option swaps
Derivative [Line Items]
Notional Value	50,000	50,000
Derivative Assets	0	0
Derivative Liabilities	$ 42	$ 430