CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Comprehensive loss
Net loss	$ (83,333)	$ (30,781)	$ (20,849)
Other comprehensive loss:
Net unrealized gain on short-term investments	2
Reclassification of gains included in net loss	(3)
Total other comprehensive loss	(1)
Comprehensive loss	$ (83,334)	$ (30,781)	$ (20,849)