Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Consolidated Statements of Comprehensive Loss (Unaudited) [Abstract]
Net loss	$ (18,680)	$ (15,767)	$ (38,131)	$ (31,110)
Other comprehensive loss
Net unrealized gain (loss) on investment	233	(89)	271	(79)
Total comprehensive loss	$ (18,447)	$ (15,856)	$ (37,860)	$ (31,189)

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

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