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 Comprehensive Income [Abstract]
Net loss	$ (22,792)	$ (14,000)	$ (48,365)	$ (25,777)
Other comprehensive income:
Unrealized gain on available-for-sale securities	26		43
Comprehensive loss	$ (22,766)	$ (14,000)	$ (48,322)	$ (25,777)

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

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