Consolidated Statements of Stockholders' Equity (Deficit) - USD ($)
$ in Thousands
Common Stock [Member]
Series A Convertible Preferred Stock [Member]
Additional Paid-In Capital [Member]
Accumulated Deficit [Member]
Total
Balance at Dec. 31, 2014 $ 34 $ 483,909 $ (459,559) $ 24,384
Balance, Shares at Dec. 31, 2014 3,364,130 [1]      
Stock-based compensation 4,117 4,117
Common Stock Warrants issued 290 290
Options exercised 99 $ 99
Options exercised, shares 6,539 [1]       (6,539)
Issuance of employee purchase plan shares 99 $ 99
Issuance of employee purchase plan shares, shares [1] 5,421        
Net loss and comprehensive loss (33,229) (33,229)
Balance at Dec. 31, 2015 $ 34 488,514 (492,788) (4,240)
Balance, Shares at Dec. 31, 2015 [1] 3,376,090        
Stock-based compensation 2,447 2,447
Common Stock Warrants issued 3,709 $ 3,709
Options exercised, shares        
Issuance of employee purchase plan shares 126 $ 126
Issuance of employee purchase plan shares, shares [1] 14,105        
Common stock issued $ 19 9,613 9,632
Common stock issued, shares [1] 1,861,090        
Series A Convertible Preferred stock issued 2,275 2,275
Series A Convertible Preferred stock issued, shares [1] 3,292      
Series A Convertible Preferred conversion to common $ 1 (1)
Series A Convertible Preferred conversion to common, shares 70,333 [1] (528)      
Exchanged shares 250 250
Exchanged shares, shares 38,580        
Net loss and comprehensive loss (19,920) (19,920)
Balance at Dec. 31, 2016 $ 54 $ 506,933 $ (512,708) $ (5,721)
Balance, Shares at Dec. 31, 2016 5,360,198 [1] 2,764      
[1] Restated for a 1-for-10 reverse stock split effected February 27, 2017.