Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
Net loss	$ (27,377)	$ (24,581)	$ (56,251)	$ (55,154)
Other comprehensive (loss) income:
Foreign currency translation adjustment	(13)	15	(10)	21
Comprehensive loss	$ (27,390)	$ (24,566)	$ (56,261)	$ (55,133)

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

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