Derivative Instruments - Notional Value and Fair Value of Derivative Instruments (Details) - Not Designated as Hedging Instrument - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Derivative [Line Items]
Notional Value	$ 525,151	$ 510,544
Derivative Assets	18,261	24,712
Derivative Liabilities	14,665	13,712
Exchange-traded futures
Derivative [Line Items]
Notional Value	174,162	154,687
Derivative Assets	1,517	1,768
Derivative Liabilities	1,226	162
Currency forwards
Derivative [Line Items]
Notional Value	37,414	34,597
Derivative Assets	4,703	4,446
Derivative Liabilities	4,593	5,047
Interest rate swaps
Derivative [Line Items]
Notional Value	16,850	16,847
Derivative Assets	581	386
Derivative Liabilities	451	262
Credit default swaps
Derivative [Line Items]
Notional Value	186,110	225,671
Derivative Assets	11,428	17,507
Derivative Liabilities	6,304	7,302
Total return swaps
Derivative [Line Items]
Notional Value	60,615	28,742
Derivative Assets	32	605
Derivative Liabilities	1,628	933
Option swaps
Derivative [Line Items]
Notional Value	50,000	50,000
Derivative Assets	0	0
Derivative Liabilities	$ 463	$ 6