Convertible Notes and Credit Facilities (Tables)

12 Months Ended

Dec. 31, 2019

Debt Instrument [Line Items]

Schedule of Carrying Values and Estimated Fair Values of Debt Instruments

The following table presents the components of the 2020 Notes as of December 31, 2019 and December 31, 2018 (in thousands, except for years and percentages):

	December 31,
	2019			2018
Liability:
Principal amount	$	45,785		$	128,250
Less: Debt discount, net of amortization	(2,151		)	(11,996		)
Less: Debt issuance costs, net of amortization	(259		)	(1,446		)
Carrying amount	$	43,375		$	114,808
Remaining amortization period (years)	0.9 years			1.9 years
Effective interest rate on liability component	9.94		%	9.94		%

Convertible Interest Expense Recognized

The following table presents interest expense recognized for the 2020 Notes and the 2024 Notes (in thousands):

	Year ended December 31,
	2019		2018		2017
Contractual interest expense	$	4,835	$	5,130	$	5,130
Amortization of debt discount	6,013		5,408		4,898
Amortization of debt issuance costs	743		652		591
Total interest expense recognized	$	11,591	$	11,190	$	10,619

Schedule of Debt

The Company has a variety of debt and credit facilities in France to satisfy the financing requirements of the operations of its French subsidiary. These arrangements are summarized in the table below (in thousands):

	December 31,
	2019			2018
Financing from French government agencies related to various government incentive programs (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.

Schedule of Maturities of Long-term Debt

The table below presents the future minimum repayments of debts and finance lease obligations in France as of December 31, 2019 (in thousands):

Years ending December 31,	Finance lease obligations		Other Debt obligations
2020	49		6,664
2021	22		5,216
2022	—		4,897
2023	—		151
2024	—		112
Thereafter	—		112
Total	$	71	$	17,152

Convertible Note due 2024 [Member]

Debt Instrument [Line Items]

Schedule of Carrying Values and Estimated Fair Values of Debt Instruments

	December 31,
	2019
Liability:
Principal amount	115,500
Less: Debt discount, net of amortization	(23,652		)
Less: Debt issuance costs, net of amortization	(3,219		)
Carrying amount	$	88,629
Remaining amortization period (years)	4.7 years
Effective interest rate on liability component	7.95		%

Convertible Note due 2020 [Member]

Debt Instrument [Line Items]

Schedule of Carrying Values and Estimated Fair Values of Debt Instruments

The following table presents the components of the 2020 Notes as of December 31, 2019 and December 31, 2018 (in thousands, except for years and percentages):

	December 31,
	2019			2018
Liability:
Principal amount	$	45,785		$	128,250
Less: Debt discount, net of amortization	(2,151		)	(11,996		)
Less: Debt issuance costs, net of amortization	(259		)	(1,446		)
Carrying amount	$	43,375		$	114,808
Remaining amortization period (years)	0.9 years			1.9 years
Effective interest rate on liability component	9.94		%	9.94		%