CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS
Net loss	$ (10,541)	$ (21,653)	$ (31,458)	$ (33,286)
Unrealized gains (losses) on available-for-sale securities:
Unrealized gains (losses) on available-for-sale securities, net of tax	(1)	(17)	35	5
Comprehensive loss	$ (10,542)	$ (21,670)	$ (31,423)	$ (33,281)