Investments - Narrative (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2025 USD ($) issuer	Mar. 31, 2024 USD ($)	Dec. 31, 2024 USD ($)
Gain (Loss) on Securities [Line Items]
Bank loan participations	$ 144,014		$ 142,410
Unpaid principal balance	151,100
Net investment income	3,200	$ 4,500
Net realized and unrealized losses on bank loan participations	$ 2,314	281
Unrealized losses		$ 530
Fixed Maturity Securities
Gain (Loss) on Securities [Line Items]
Number of issuers | issuer	420
Total fair value	$ 947,516		1,012,365
Gross unrealized losses	$ 74,720		$ 90,706
Fixed Maturity Securities | BBB- or better
Gain (Loss) on Securities [Line Items]
Percentage of available for sale securities	100.00%