CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (unaudited) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net loss		$ (16,310)	$ (102,362)	$ (52,565)	$ (129,542)
Other comprehensive loss:
Foreign currency translation losses	[1]	(2,950)	(72)	(2,162)	(334)
Total other comprehensive loss	[1]	(2,950)	(72)	(2,162)	(334)
Total comprehensive loss		$ (19,260)	$ (102,434)	$ (54,727)	$ (129,876)

[1] Net of tax effect which was not material.