Other Non-Operating Income (Details 1) - USD ($) $ in Thousands	3 Months Ended							9 Months Ended		12 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Dec. 31, 2017
Other Nonoperating Income (Expense) [Abstract]
Gain on sale of equity affiliate	$ 0				$ 0			$ 28,994	$ 0
Gain on cost method investments	3,669		$ 1,300		8,487			5,080	8,487
Foreign currency gain (loss), net	661				(116)			1,284	(2,205)
Impairment of a cost method investment	0				(2,500)			0	(2,500)
Gain on sales of businesses	486				916			907	8,157
Gain on sale of cost method investments	259				0			259	2,845
(Loss) gain on sale of property, plant and equipment	(38)				0			(82)	2,542
Other gain (loss), net	519				(3,645)			(307)	(2,664)
Total Other Non-Operating Income	$ 5,556	$ 1,228	$ 29,351	$ (12,559)	$ 3,142	$ 2,333	$ 9,187	$ 36,135	$ 14,662	$ 2,103	$ 4,241