Investments - Rollforward of the Allowance for Credit Losses on Available-for-sale Securities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Investments Debt And Equity Securities [Abstract]
Allowance for credit losses, beginning of period	$ 816
Additions to the allowance for credit losses on securities for which credit losses were not previously recorded		$ 821	$ 525
Additional increases (or decreases) to the allowance for credit losses on securities that had an allowance recorded in a previous period	(81)	(5)	(51)
Write-offs charged against the allowance, if any	$ (735)		$ (474)
Allowance for credit losses, end of period		$ 816