Investments - Additional Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2026 USD ($) security	Mar. 31, 2025 USD ($)	Dec. 31, 2025 USD ($)
Investments
Accrued investment income | $	$ 30,456		$ 30,026
Number of debt securities for which there is an allowance for credit losses | security	8
Losses on fixed income securities | $	$ 1,000	$ 0
Number of debt securities in an unrealized loss position for which an allowance for credit losses has not been recorded | security	1,328
Unrealized loss | $	$ 156,209		140,435
Unrealized losses as percentage of fixed income portfolio cost basis	4.00%
Unrealized losses relative to total invested assets (as a percent)	3.00%
Number of unrealized loss positions | security	1,328
Number of securities in unrealized loss positions for 12 months or longer | security	777
Fixed Income Securities
Investments
Accrued investment income | $	$ 29,000		$ 29,000