Convertible Notes - Other Debts and Capital Leases (Details) - USD ($) $ in Thousands		Dec. 31, 2019	Dec. 31, 2018
Debt Disclosure [Abstract]
Financing from French government agencies related to various government incentive programs (1)	[1]	$ 16,566	$ 18,783
Term loans		587	914
Obligations under finance leases		71	162
Total debt obligations		17,224	19,859
Less: current portion		(6,713)	(7,175)
Long-term portion		$ 10,511	$ 12,684

[1] Loans backed by French R&D tax credit receivables were $15.1 million and $16.7 million as of December 31, 2019 and 2018, respectively. As of December 31, 2019, the French Subsidiary had an aggregate of $23.2 million of R&D tax credit receivables from the French government from 2020 through 2023. (See Note 10, “Certain Balance Sheet Components-Prepaid expenses and other current assets” for more information). These tax loans have a fixed rate of 0.6%, plus EURIBOR 1 month plus 1.3% and mature between 2020 through 2022. The remaining loans of $1.5 million and $2.1 million as of December 31, 2019 and 2018, respectively, primarily relate to financial support from French government agencies for R&D innovation projects at minimal interest rates, and the loans outstanding at December 31, 2019 mature between 2020 through 2025.