Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net loss	$ (1,109)	$ (24,801)	$ (11,791)	$ (40,343)
Other comprehensive income (loss):
Unrealized gain on investments, net of tax			12	5
Unrealized gain (loss) on currency translation		(2)	8	2
Other comprehensive income (loss)		(2)	20	7
Comprehensive loss	$ (1,109)	$ (24,803)	$ (11,771)	$ (40,336)