Condensed 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	$ (20,037)	$ (20,601)	$ (41,935)	$ (39,803)
Change in unrealized gain on short-term investments	183	46	244	33
Comprehensive loss	$ (19,854)	$ (20,555)	$ (41,691)	$ (39,770)

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

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