CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net loss		$ (73,859)	$ (154,740)	$ (24,010)
Other comprehensive loss:
Foreign currency translation losses	[1]	(157)	(306)	(68)
Total other comprehensive loss	[1]	(157)	(306)	(68)
Total comprehensive loss		$ (74,016)	$ (155,046)	$ (24,078)

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