Investments - Additional Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2025 USD ($) security	Mar. 31, 2024 USD ($)	Dec. 31, 2024 USD ($)
Investments
Accrued investment income | $	$ 27,932		$ 28,319
Number of debt securities for which there is an allowance for credit losses | security	9
Losses on fixed income securities | $	$ 0	$ 0
Number of debt securities in an unrealized loss position for which an allowance for credit losses has not been recorded | security	1,378
Unrealized loss | $	$ 189,636		224,611
Unrealized losses as percentage of fixed income portfolio cost basis	5.00%
Unrealized losses relative to total invested assets (as a percent)	5.00%
Number of unrealized loss positions | security	1,378
Number of securities in unrealized loss positions for 12 months or longer | security	982
Fixed Income Securities
Investments
Accrued investment income | $	$ 27,000		$ 27,000