Restructuring Costs - (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ (169)	$ 1,164
Fixed asset impairment		66,087
Restructuring reserve	28	879	$ 1,000
2019 French Restructuring Obligation
Restructuring Cost and Reserve [Line Items]
Restructuring costs	4,855
Operating lease, impairment loss	629
Fixed asset impairment	887
Restructuring reserve	1,922	0
2019 French Restructuring Obligation | Employee Severance
Restructuring Cost and Reserve [Line Items]
Charges for employee severance, benefits and other costs	4,339
2019 French Restructuring Obligation | Retirement Indemnity Obligation
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 1,000
Corporate Workforce Reduction | Employee Severance
Restructuring Cost and Reserve [Line Items]
Percent reduction in workforce	50.00%
2019 Corporate Restructuring Obligations
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 1,755
Fixed asset impairment	288
Write-off of property, plant and equipment	125
Restructuring reserve	1,080	0
Share-based compensation forfeitures related to the employees affected by the global reduction in workforce	2,064
2019 Corporate Restructuring Obligations | Employee Severance
Restructuring Cost and Reserve [Line Items]
Restructuring costs	3,406
Lyon France Workforce Reduction | Employee Severance
Restructuring Cost and Reserve [Line Items]
Charges for employee severance, benefits and other costs		1,164
Percent reduction in workforce				50.00%
Share-based compensation forfeitures related to the employees affected by the global reduction in workforce	169
Accrued Liabilities | 2019 French Restructuring Obligation
Restructuring Cost and Reserve [Line Items]
Restructuring reserve	$ 1,849	$ 42	$ 31