CONDENSED 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
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (26,270)	$ (12,426)	$ (50,122)	$ (22,643)
Other comprehensive gain:
Change in unrealized gain (loss) on available for sale securities, net	180	38	263	25
Total other comprehensive gain	180	38	263	25
Comprehensive loss	$ (26,090)	$ (12,388)	$ (49,859)	$ (22,618)

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

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