Consolidated Statements of Comprehensive Loss Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Net loss	$ (46,195)	$ (30,555)	$ (33,227)
Unrealized loss on available-for-sale investments, net of tax	(61)	0	0
Comprehensive loss	$ (46,256)	$ (30,555)	$ (33,227)