Investments (Gains (Losses) on Equity Securities) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Investments, Debt and Equity Securities [Abstract]
Net losses during the period	$ (3,196)	$ (75,560)	$ (23,184)	$ (66,609)
Less: (losses) gains on securities sold during the period	0	(48,243)	357	(48,243)
Unrealized loss on short-term investments held at the reporting date, net	$ (3,196)	$ (27,317)	$ (23,541)	$ (18,366)