Restructuring Costs - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring (income) costs	$ (226)	$ 1,866	$ (43)	$ 4,600
2019 French Restructuring Obligation
Restructuring Cost and Reserve [Line Items]
Restructuring (income) costs		1,259		3,198
Fixed asset impairment				598
Benefit related to the reversal of retirement indemnity obligation				1,000
Restructuring reserve	237	895	237	895	$ 1,922	$ 0
2019 French Restructuring Obligation | Accrued Liabilities
Restructuring Cost and Reserve [Line Items]
Restructuring reserve	237		237
2019 Corporate Restructuring Obligations
Restructuring Cost and Reserve [Line Items]
Restructuring (income) costs		607		1,570
Restructuring reserve	$ 492	$ 853	$ 492	853	$ 1,080	$ 0
Benefit related to share based compensation forfeitures related to the employees				1,396
Employee Severance | 2019 French Restructuring Obligation
Restructuring Cost and Reserve [Line Items]
Restructuring (income) costs				$ 2,774
Employee Severance | Corporate Workforce Reduction
Restructuring Cost and Reserve [Line Items]
Expected number of positions eliminated (as a percent)		50.00%		50.00%
Employee Severance | 2019 Corporate Restructuring Obligations
Restructuring Cost and Reserve [Line Items]
Restructuring (income) costs				$ 2,966
Facility Closing | 2019 French Restructuring Obligation
Restructuring Cost and Reserve [Line Items]
Restructuring (income) costs				$ 826