CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (Unaudited) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS [Abstract]
Net loss	$ (62,046)	$ (20,359)	$ (91,673)	$ (84,214)
Unrealized gains (losses) on investments, net of tax	151	1	106	(27)
Currency translation adjustment	20	(42)	48	(36)
Comprehensive loss	$ (61,875)	$ (20,400)	$ (91,519)	$ (84,277)

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

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