Restructuring Activities - Charges (Details) - USD ($) $ in Thousands		3 Months Ended
	Jan. 23, 2019	Jun. 30, 2019	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Restructuring Cost and Reserve [Line Items]
Total Revenues			$ 10,155	$ 12,791
Net loss			(1,289)	(216)
Total assets			47,245		$ 51,719
Liabilities			(14,262)		(17,667)
Payments for restructuring			287	109
Restructuring charge			595	0
CHINA
Restructuring Cost and Reserve [Line Items]
Total Revenues			338	659
Net loss			(850)	$ (533)
Total assets			7,719		12,126
Liabilities			(2,809)		(4,642)
Net Assets			4,910		$ 7,484
CHINA | Employee Severance
Restructuring Cost and Reserve [Line Items]
Restructuring, expected cost			632
Payments for restructuring			257
Restructuring charge			532
CHINA | Facility Closing
Restructuring Cost and Reserve [Line Items]
Restructuring charge	$ 63		$ 63
Scenario, Forecast | CHINA | Employee Severance
Restructuring Cost and Reserve [Line Items]
Payments for restructuring		$ 375