STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
STATEMENTS OF COMPREHENSIVE LOSS
Net income (loss)	$ 46	$ (35,670)	$ (38,379)
Net unrealized loss on marketable securities	(129)	(70)	(54)
Comprehensive loss	$ (83)	$ (35,740)	$ (38,433)