Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (76,333)	$ (84,979)
Other comprehensive loss:
Unrealized loss on cash flow hedge		350
Comprehensive loss	$ (76,333)	$ (84,629)