Statements of Stockholders' Equity - USD ($)
shares in Thousands, $ in Thousands
Total
Common Stock [Member]
Additional Paid-in Capital [Member]
Accumulated Deficit [Member]
Accumulated Other Comprehensive Income/(loss) [Member]
Beginning Balance at Dec. 31, 2013 $ 61,412 $ 87 $ 440,489 $ (379,175) $ 11
Beginning Balance, shares at Dec. 31, 2013   8,678      
Net loss (16,492)     (16,492)  
Other comprehensive income (loss) (23)       (23)
Issuance of common stock 3,923 $ 3 3,920    
Issuance of common stock, shares   329      
Issuance of common stock underlying restricted stock units net of shares withheld to settle withholding taxes (57) $ 1 (58)    
Issuance of common stock underlying restricted stock units net of shares withheld to settle withholding taxes, shares   26      
Non-cash compensation expense related to grant of equity based compensation 3,159   3,159    
Ending Balance at Dec. 31, 2014 51,922 $ 91 447,510 (395,667) (12)
Ending Balance, shares at Dec. 31, 2014   9,033      
Net loss (9,238)     (9,238)  
Other comprehensive income (loss) 52       52
Issuance of common stock 775 $ 1 774    
Issuance of common stock, shares   86      
Issuance of common stock underlying restricted stock units net of shares withheld to settle withholding taxes (20)   (20)    
Issuance of common stock underlying restricted stock units net of shares withheld to settle withholding taxes, shares   35      
Non-cash compensation expense related to grant of equity based compensation 1,902   1,902    
Ending Balance at Dec. 31, 2015 $ 45,393 $ 92 450,166 (404,905) 40
Ending Balance, shares at Dec. 31, 2015 9,154 9,154      
Net loss $ (8,973)     (8,973)  
Other comprehensive income (loss) (15)       (15)
Issuance of common stock 7,753 $ 18 7,735    
Issuance of common stock, shares   1,841      
Issuance of common stock underlying restricted stock units net of shares withheld to settle withholding taxes (9) $ 1 (10)    
Issuance of common stock underlying restricted stock units net of shares withheld to settle withholding taxes, shares   57      
Non-cash compensation expense related to grant of equity based compensation 990   990    
Ending Balance at Dec. 31, 2016 $ 45,139 $ 111 $ 458,881 $ (413,878) $ 25
Ending Balance, shares at Dec. 31, 2016 11,052 11,052