Restructuring Costs - France - Severance Obligation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Restructuring Reserve [Roll Forward]
Beginning balance of accrued costs	$ 1,000	$ 0
Charges for employee severance, benefits and other	1,164	3,259
Payments	(1,261)	(2,600)
Foreign currency impact	(24)	341
Ending balance of accrued costs	$ 879	$ 1,000