Annual report pursuant to Section 13 and 15(d)

Long-Term Debt and Other Financings - General Electric Capital Corporation Term Loan - Additional Information (Details)

v3.6.0.2
Long-Term Debt and Other Financings - General Electric Capital Corporation Term Loan - Additional Information (Details) - USD ($)
 1 Months Ended 12 Months Ended
Feb. 27, 2015
Sep. 27, 2012
Feb. 29, 2016
Sep. 30, 2012
Dec. 31, 2011
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Debt Instrument [Line Items]                
Aggregate number of unregistered shares of common stock called by warrants (in shares)     8,249          
Exercise price of warrants (in dollars per share)     $ 15.40          
Exercisable period of warrants     5 years          
Estimated fair value of warrants     $ 100,000          
Repayment of principal           $ 6,890,000 $ 6,128,000 $ 5,917,000
Loss on extinguishment of debt             (429,000)  
GECC Term Loan [Member]                
Debt Instrument [Line Items]                
Aggregate number of unregistered shares of common stock called by warrants (in shares)   1,967     13,158      
Exercise price of warrants (in dollars per share)   $ 70.80     $ 22.80      
Exercisable period of warrants   5 years     5 years      
Warrants expiration period   2017-09     2016-12      
Increase in term loan obligation       $ 4,600,000        
Amended balance of the term loan       12,500,000        
Debt issuance costs       200,000        
Final payment fee       $ 875,000 $ 500,000      
Estimated fair value of warrants   $ 100,000     $ 200,000      
Repayment of principal $ 5,500,000              
Loss on extinguishment of debt             $ (400,000)  
Hercules Term Loan [Member]                
Debt Instrument [Line Items]                
Aggregate number of unregistered shares of common stock called by warrants (in shares) 9,063              
Exercise price of warrants (in dollars per share) $ 66.20              
Exercisable period of warrants 5 years              
Warrants expiration period 2020-02              
Debt issuance costs $ 500,000              
Final payment fee 1,200,000              
Estimated fair value of warrants 500,000              
Proceeds from loans $ 20,000,000