Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Statement of Comprehensive Income [Abstract]
Net loss	$ (7,333)	$ (8,348)
Other comprehensive income (loss):
Unrealized gain on investments, net of tax	5	6
Unrealized loss on currency translation	(2)
Other comprehensive income	3	6
Comprehensive loss	$ (7,330)	$ (8,342)