Investments - Narrative (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025 USD ($) issuer	Jun. 30, 2024 USD ($)	Jun. 30, 2025 USD ($) issuer	Jun. 30, 2024 USD ($)	Dec. 31, 2024 USD ($)
Gain (Loss) on Securities [Line Items]
Bank loan participations	$ 158,871		$ 158,871		$ 142,410
Unpaid principal balance	164,600		164,600
Net investment income	3,100	$ 4,600	6,300	$ 9,100
Net realized and unrealized gains (losses) on bank loan participations	$ 253	(843)	$ (2,061)	(1,124)
Unrealized losses		1,400		$ 2,600
Fixed Maturity Securities
Gain (Loss) on Securities [Line Items]
Number of issuers | issuer	402		402
Total fair value	$ 890,016		$ 890,016		1,012,365
Gross unrealized losses	$ 70,248		$ 70,248		$ 90,706
Impairment loss		$ 207
Fixed Maturity Securities | BBB- or better
Gain (Loss) on Securities [Line Items]
Percentage of available for sale securities	100.00%		100.00%