Costs Associated with Exit and Restructuring Activities - Restructuring Reserve Activity (Details) - June 2013 Plan, April 2014 Plan and June 2016 Plan $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($)
Restructuring reserve activity
Restructuring liability at beginning	$ 1,913
Restructuring and restructuring-related charges	1,195
Cost paid	(1,376)
Restructuring liability at ending	1,724
Restructuring Reserve, Translation and Other Adjustment	$ (8)