Statement of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Cash Flows [Abstract]
Realized loss/(gain) on sale of marketable securities	$ 0	$ (5)	$ (189)
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability	(8,917)	(3,000)	0
Payments to Noncontrolling Interests	$ 0	$ (1,444)	$ 1,183