Investments - Portion of Net Unrealized Gains (Losses) Recognized During the Reporting Period (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Equity securities:
Net gains (losses) recognized during the period	$ 244	$ (1,624)	$ (3,060)	$ (14,727)
Less: net gains (losses) recognized on securities sold	91	243	(2,636)	(1,327)
Net unrealized gains (losses) recognized on securities held at reporting date	$ 153	$ (1,867)	$ (424)	$ (13,400)