Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement of Comprehensive Income [Abstract]
Net loss	$ (24,801)	$ (48,196)	$ (40,343)	$ (65,124)
Other comprehensive income (loss):
Unrealized gain on investments, net of tax		5	5	15
Unrealized gain (loss) on currency translation	(2)	2	2	1
Other comprehensive income (loss)	(2)	7	7	16
Comprehensive loss	$ (24,803)	$ (48,189)	$ (40,336)	$ (65,108)