Investments - Disposition of Fixed Income and Equity Securities (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Summary of the disposition of fixed income and equity securities
Fixed income securities - available-for-sale	$ 19,490	$ 20,892
Fixed income securities - available-for-sale	349,714	137,476
SALES
Summary of the disposition of fixed income and equity securities
Fixed income securities - available-for-sale	20,729	19,390
Gross Realized Gains - Fixed income securities - available-for-sale	99	215
Gross Realized Losses - Fixed income securities - available-for-sale	(910)	(432)
Net Realized Gain (Loss) - Fixed income securities - available-for-sale	(811)	(217)
Proceeds from Sales - Equity securities	22,029	53,525
Gross Realized Gains - Equity securities	8,841	19,244
Gross Realized Losses - Equity securities	(101)	(15)
Net Realized Gain (Loss) - Equity securities	8,740	19,229
Calls And Maturities Of Marketable Securities
Summary of the disposition of fixed income and equity securities
Fixed income securities - available-for-sale	349,734	137,499
Gross Realized Gains - Fixed income securities - available-for-sale	37	76
Gross Realized Losses - Fixed income securities - available-for-sale	(43)	(55)
Net Realized Gain (Loss) - Fixed income securities - available-for-sale	$ (6)	$ 21