Restructuring Costs (Details 2) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restructuring Cost and Reserve [Line Items]
Restructuring expenses	$ 625	$ 1,431	$ 1,361
Total COGS and SGA
Restructuring Cost and Reserve [Line Items]
Restructuring expenses	$ 600	$ 1,400	$ 1,361