Restructuring Costs - Narrative (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2019
2019 French Restructuring Obligation
Restructuring Cost and Reserve [Line Items]
Restructuring reserve	$ 117	$ 248
2019 French Restructuring Obligation | Accrued Liabilities
Restructuring Cost and Reserve [Line Items]
Restructuring reserve	117
Corporate Workforce Reduction | Employee Severance
Restructuring Cost and Reserve [Line Items]
Expected number of positions eliminated (as a percent)			50.00%
2019 Corporate Restructuring Obligations
Restructuring Cost and Reserve [Line Items]
Restructuring reserve	$ 170	$ 272