Other Non-Operating Income (Details 1) - USD ($) $ in Thousands	3 Months Ended					9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019
Other Nonoperating Income (Expense) [Abstract]
Gain on cost method investments	$ 1,638	$ 2,600		$ 3,669	$ 1,400	$ 4,209	$ 5,080
Gain on acquiring a controlling interest in an equity affiliate	0			0		3,708	0
Impairment of cost method investments	0		$ (2,600)	0		(2,577)	0
Gain on sale of businesses	755			486		2,515	907
Gain on sale of equity affiliates	0			0		1,370	28,994
Gain on sale of cost method investments	521			259		1,039	259
Foreign currency (loss) gain, net	(2,343)			661		877	1,284
Other (loss) gain, net	(349)			481		(131)	(389)
Total Other Non-Operating Income	$ 222			$ 5,556		$ 11,010	$ 36,135