Investments - Investments in Debt and Equity Securities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Cost
Equity	$ 304,305	$ 262,564
Debt	774,580	613,271
Other	19,102	11,431
Total	1,097,987	887,266
Gross Unrealized Gains
Equity	280,127	219,658
Debt	4,859	18,090
Other	0	0
Total	284,986	237,748
Gross Unrealized Losses
Equity	(4,682)	(8,127)
Debt	(7,001)	(641)
Other	(1)	0
Total	(11,684)	(8,768)
Fair Value
Equity	579,750	474,095
Debt	772,438	630,720
Other	19,101	11,431
Total	$ 1,371,289	$ 1,116,246