Restructuring Charges (Details 2) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	$ 2,029	$ 1,530
Restructuring Charges		800	$ 6,700
Restructuring Costs	18,772	774
Restructuring Reserve, Current	1,290	423	6,539
Payments for Restructuring	(18,256)	(5,869)
Restructuring Reserve, Foreign Currency Translation Gain (Loss)		(134)
Restructuring Reserve, Accrual Adjustment	(17)	(48)
Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	915	53	2,505
Restructuring Charges		600	1,900
Restructuring Costs	15,983	25
Payments for Restructuring	(15,104)	(2,683)
Restructuring Reserve, Foreign Currency Translation Gain (Loss)		(77)
Restructuring Reserve, Accrual Adjustment	(17)	129
government incentive repayment [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	0	0	1,884
Restructuring Costs	0	0
Payments for Restructuring	0	(1,769)
Restructuring Reserve, Foreign Currency Translation Gain (Loss)		(57)
Restructuring Reserve, Accrual Adjustment	0	(172)
Special Termination Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	1,114	1,477	1,845
Restructuring Costs	0
Buy-out agreement		0
Payments for Restructuring	(363)	(368)
Restructuring Reserve, Foreign Currency Translation Gain (Loss)		0
Restructuring Reserve, Accrual Adjustment	0	0
Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	0	0	305
Restructuring Costs	0	168
Payments for Restructuring	0	(468)
Restructuring Reserve, Foreign Currency Translation Gain (Loss)		0
Restructuring Reserve, Accrual Adjustment	0	(5)
Business Restructuring Reserves [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges			4,200
Facility Closing [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	0	0	$ 0
Restructuring Charges	2,789	581
Payments for Restructuring	(2,789)	(581)
Restructuring Reserve, Foreign Currency Translation Gain (Loss)		0
Restructuring Reserve, Accrual Adjustment	$ 0	$ 0