CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $) In Thousands, except Share data, unless otherwise specified	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Other Comprehensive Income (Expense) [Member]	Total
Balance at Dec. 31, 2011	$ 5	$ 104,277	$ (36,001)	$ (4)	$ 68,277
Balance (in shares) at Dec. 31, 2011	50,619,136
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issued for cash exercise of warrants, net		161			161
Stock issued for cash exercise of warrants (in shares)	44,941
Stock-based compensation		6,162			6,162
Deferred tax benefit related to stock based compensation		3,111			3,111
Derivative liability		1,454			1,454
Exercise of options		1,691			1,691
Exercise of options (in shares)	486,165
Comprehensive income:
Net loss			(26,924)		(26,924)
Other comprehensive income net of tax				12	12
Comprehensive loss					(26,912)
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 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
Derivative liability		7			7
Exercise of options		278			278
Exercise of options (in shares)	679,321
Vested RSUs (in shares)	78,739
Comprehensive income:
Net loss			(9,902)		(9,902)
Other comprehensive income 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