Investments - Schedule of Alternative Investment Portfolio by Strategy and the Remaining Commitment Amount and Maximum Exposure to Loss Associated With Each Strategy (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Other Investment Portfolio By Strategy And Remaining Commitment Amount and Maximum Exposure to Loss Associated With Each Strategy [Line Items]
Carrying Value	$ 414,780	$ 395,779
Private equity
Other Investment Portfolio By Strategy And Remaining Commitment Amount and Maximum Exposure to Loss Associated With Each Strategy [Line Items]
Carrying Value	319,236	301,759
Remaining Commitment	148,558	131,885
Maximum Exposure to Loss	467,794	433,644
Private credit
Other Investment Portfolio By Strategy And Remaining Commitment Amount and Maximum Exposure to Loss Associated With Each Strategy [Line Items]
Carrying Value	52,106	54,500
Remaining Commitment	98,417	89,401
Maximum Exposure to Loss	150,523	143,901
Real assets
Other Investment Portfolio By Strategy And Remaining Commitment Amount and Maximum Exposure to Loss Associated With Each Strategy [Line Items]
Carrying Value	43,438	39,520
Remaining Commitment	42,336	33,040
Maximum Exposure to Loss	85,774	72,560
Total alternative investments
Other Investment Portfolio By Strategy And Remaining Commitment Amount and Maximum Exposure to Loss Associated With Each Strategy [Line Items]
Carrying Value	414,780	395,779
Remaining Commitment	289,311	254,326
Maximum Exposure to Loss	$ 704,091	$ 650,105