Condensed Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (18,728)	$ (17,167)
Other comprehensive (loss) income:
Unrealized (loss) gain on marketable securities	(185)	40
Total comprehensive loss	$ (18,913)	$ (17,127)

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

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