Restructuring Costs - Severance Obligation (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Restructuring Reserve [Roll Forward]
Restructuring costs	$ 159	$ 1,228
2019 Corporate Restructuring Obligations
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	1,080	0
Payments	(202)	(754)
Restructuring reserve, ending balance	940	644
2019 French Restructuring Obligation
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	1,922
Payments	(1,294)
Foreign currency impact	(34)
Restructuring reserve, ending balance	765
Employee Severance | 2019 Corporate Restructuring Obligations
Restructuring Reserve [Roll Forward]
Restructuring costs	62	$ 1,398
Employee Severance | 2019 French Restructuring Obligation
Restructuring Reserve [Roll Forward]
Restructuring costs	$ 171