Derivative Instruments - Notional Value and Fair Value of Derivative Instruments (Details) - Not Designated as Hedging Instrument - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Derivative [Line Items]
Notional Value	$ 535,905	$ 510,544
Derivative Assets	16,687	24,712
Derivative Liabilities	16,411	13,712
Exchange-traded futures
Derivative [Line Items]
Notional Value	164,368	154,687
Derivative Assets	4	1,768
Derivative Liabilities	4,878	162
Currency forwards
Derivative [Line Items]
Notional Value	35,796	34,597
Derivative Assets	4,456	4,446
Derivative Liabilities	5,019	5,047
Interest rate swaps
Derivative [Line Items]
Notional Value	14,890	16,847
Derivative Assets	204	386
Derivative Liabilities	162	262
Credit default swaps
Derivative [Line Items]
Notional Value	218,604	225,671
Derivative Assets	11,796	17,507
Derivative Liabilities	4,882	7,302
Total return swaps
Derivative [Line Items]
Notional Value	52,247	28,742
Derivative Assets	227	605
Derivative Liabilities	1,178	933
Option swaps
Derivative [Line Items]
Notional Value	50,000	50,000
Derivative Assets	0	0
Derivative Liabilities	$ 292	$ 6