Investments - Disposition of Fixed Income and Equity Securities (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Summary of the disposition of fixed income and equity securities
Fixed income securities - available-for-sale	$ 80,245	$ 26,158
Fixed income securities - available-for-sale	242,955	414,529
Net Realized Gain (Loss) - Fixed income securities - available-for-sale	0	(2,000)
SALES
Summary of the disposition of fixed income and equity securities
Fixed income securities - available-for-sale	98,696	25,983
Gross Realized Gains - Fixed income securities - available-for-sale	538	145
Gross Realized Losses - Fixed income securities - available-for-sale	(2,489)	(1,035)
Net Realized Gain (Loss) - Fixed income securities - available-for-sale	(1,951)	(890)
Proceeds from Sales - Equity securities	44,863	36,708
Gross Realized Gains - Equity securities	20,276	15,990
Gross Realized Losses - Equity securities	(340)	(101)
Net Realized Gain (Loss) - Equity securities	19,936	15,889
Calls And Maturities Of Marketable Securities
Summary of the disposition of fixed income and equity securities
Fixed income securities - available-for-sale	240,200	434,263
Gross Realized Gains - Fixed income securities - available-for-sale	89	38
Gross Realized Losses - Fixed income securities - available-for-sale	(1,062)	(236)
Net Realized Gain (Loss) - Fixed income securities - available-for-sale	$ (973)	$ (198)