Quarterly report pursuant to Section 13 or 15(d)

Long-Term Debt - Hercules Term Loan - Additional Information (Details)

v3.7.0.1
Long-Term Debt - Hercules Term Loan - Additional Information (Details) - USD ($)
$ / shares in Units, $ in Thousands
3 Months Ended
Feb. 27, 2015
Mar. 31, 2017
Mar. 31, 2016
Dec. 31, 2016
Debt Instrument [Line Items]        
Carrying value of the loan   $ 26,629    
Loss on extinguishment of debt   $ (515)    
Warrants expiration period   2017-03    
Hercules Term Loan [Member]        
Debt Instrument [Line Items]        
Maturity date Sep. 01, 2018      
Variable rate basis   The Hercules Term Loan had a variable interest rate that was the greater of either (i) 9.40% plus the prime rate as reported from time to time in The Wall Street Journal minus 7.25%, or (ii) 9.40%.    
Period of principal and interest amortized 30 months      
Amortization of interest payments period end date Jun. 01, 2016      
Period of interest 1 month      
Additional interest rate in case of default 5.00%      
Debt issuance costs $ 500      
Final payment fee $ 1,200      
Amortization of debt discount   $ 200 $ 200  
Outstanding principal balance       $ 17,500
Carrying value of the loan       $ 16,850
Prepayment charge not required to pay   1.00%    
Loss on extinguishment of debt   $ 500    
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      
Estimated fair value of warrants $ 500      
Exercisable period of warrants 5 years      
Warrants expiration period 2020-02      
Minimum [Member] | Hercules Term Loan [Member]        
Debt Instrument [Line Items]        
Percentage bearing variable rate   9.40%    
Prime Rate [Member] | Hercules Term Loan [Member]        
Debt Instrument [Line Items]        
Basis spread, addition   9.40%    
Basis spread, subtraction   7.25%