Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (47,087)	$ (13,322)	$ (1,516)
Other comprehensive loss:
Unrealized loss on marketable securities, net	(15)
Comprehensive loss	$ (47,102)	$ (13,322)	$ (1,516)