CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (14,812)	$ (24,822)	$ (37,084)	$ (57,266)
Other comprehensive income:
Foreign currency translation adjustment		(1,027)		677
Comprehensive loss	$ (14,812)	$ (25,849)	$ (37,084)	$ (56,589)

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

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