CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Other Comprehensive Income (Expense) [Member]	Total
Balance at Dec. 31, 2012	$ 5	$ 116,856	$ (62,925)	$ 8	$ 53,944
Balance (in shares) at Dec. 31, 2012	51,150,242
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation		7,563			7,563
Exercise of options		170			170
Exercise of options (in shares)	39,833
Vested RSUs (in shares)	46,066
Comprehensive income:
Net loss			(27,608)		(27,608)
Other comprehensive income (loss), net of tax				(45)	(45)
Comprehensive loss					(27,653)
Balance at Dec. 31, 2013	$ 5	124,589	(90,533)	(37)	34,024
Balance (in shares) at Dec. 31, 2013	51,236,141
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issued for cash exercise of warrants, net		9			9
Stock issued for cash exercise of warrants (in shares)	2,500
Stock-based compensation		8,189			8,189
Exercise of options		278			278
Exercise of options (in shares)	679,321
Vested RSUs (in shares)	78,739
Derivative liability		7			7
Comprehensive income:
Net loss			(9,902)		(9,902)
Other comprehensive income (loss), net of tax				22	22
Comprehensive loss					(9,880)
Balance at Dec. 31, 2014	$ 5	133,072	(100,435)	(15)	32,627
Balance (in shares) at Dec. 31, 2014	51,996,701
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issued for cash exercise of warrants, net		431			431
Stock issued for cash exercise of warrants (in shares)	120,161
Stock issued for cash, net		3,276			3,276
Stock issued for cash, net (in shares)	835,056
Advisor warrant issuance		121			121
Stock-based compensation		7,275			7,275
Exercise of options		165			165
Exercise of options (in shares)	143,100
Vested RSUs (in shares)	103,817
Derivative liability		438			438
Comprehensive income:
Net loss			(29,234)		(29,234)
Other comprehensive income (loss), net of tax				(4)	(4)
Comprehensive loss					(29,238)
Balance at Dec. 31, 2015	$ 5	$ 144,778	$ (129,669)	$ (19)	$ 15,095
Balance (in shares) at Dec. 31, 2015	53,198,835