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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Description of Business and Basis of Presentation (Details)	3 Months Ended
	Mar. 31, 2019 USD ($) product	Mar. 31, 2018 USD ($)	Jan. 01, 2019 USD ($)	Dec. 31, 2018 USD ($)	Nov. 08, 2018 USD ($)
Debt Instrument [Line Items]
Number of commercial products \| product	2
Net loss	$ 31,847,000	$ 32,828,000
Net cash inflow from operating activities	8,150,000	$ (22,731,000)
Short-term debt	73,928,000			$ 73,677,000
Operating lease right-of-use asset	1,300,000
Operating lease liability	1,335,000
Intercompany Loan
Debt Instrument [Line Items]
Short-term debt					$ 3,500,000
Secured Debt \| Bridge Credit Agreement
Debt Instrument [Line Items]
Loan aggregate amount	74,400,000
Secured Debt \| Intercompany Loan
Debt Instrument [Line Items]
Short-term debt	35,700,000
Convertible Notes
Debt Instrument [Line Items]
Principal amount of convertible notes	$ 302,500,000
Debt instrument, stated interest rate percentage	2.00%
Loan aggregate amount	$ 302,498,000			$ 302,498,000
ASU 2016-02
Debt Instrument [Line Items]
Operating lease right-of-use asset			$ 1,800,000
Operating lease liability			$ 1,800,000