Investments - Additional Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) security	Dec. 31, 2022 USD ($)
Investment Holdings [Line Items]
Accrued investment income	$ 24,062	$ 21,259
Number of debt securities for which there is an allowance for credit losses | security	14
Losses on fixed income securities	$ 2,000
Number of debt securities in an unrealized loss position for which an allowance for credit losses has not been recorded | security	1,267
Unrealized loss	$ 214,396	280,222
Unrealized losses as percentage of fixed income portfolio cost basis	7.00%
Unrealized losses relative to total invested assets (as a percent)	6.00%
Number of unrealized loss positions | security	1,267
Number of securities in unrealized loss positions for 12 months or longer | security	1,138
Maximum
Investment Holdings [Line Items]
Losses on fixed income securities		1,000
Fixed Income Securities
Investment Holdings [Line Items]
Accrued investment income	$ 23,000	$ 20,000