XML 79 R56.htm IDEA: XBRL DOCUMENT v3.8.0.1
Long-Term Debt - Additional Information (Detail)
1 Months Ended 12 Months Ended
Dec. 23, 2014
USD ($)
Dec. 31, 2016
USD ($)
Sep. 30, 2015
USD ($)
Dec. 31, 2017
USD ($)
Dec. 31, 2015
USD ($)
Oct. 31, 2016
USD ($)
Dec. 31, 2014
USD ($)
TRANCHES
Debt Instrument [Line Items]              
Loss on extinguishment of debt         $ (1,671,000)    
Loan and Security Agreement | Hercules Technology Growth Capital, Inc. (“Hercules”)              
Debt Instrument [Line Items]              
Maximum borrowing capacity             $ 40,000,000
Number of tranches for loan and security agreement | TRANCHES             2
Repayment of loan agreement     $ 11,000,000        
Outstanding principal     10,000,000        
Accrued unpaid interest     38,000        
Term fee     800,000        
Prepayment charges     200,000        
Loss on extinguishment of debt     1,700,000        
Loan and Security Agreement | Hercules Technology Growth Capital, Inc. (“Hercules”) | First Tranche              
Debt Instrument [Line Items]              
Proceeds from lines of credit $ 10,000,000            
Loan and Security Agreement | Hercules Technology Growth Capital, Inc. (“Hercules”) | Second Tranche              
Debt Instrument [Line Items]              
Proceeds from lines of credit       $ 0      
Available borrowing capacity     $ 30,000,000        
Note Purchase Agreement              
Debt Instrument [Line Items]              
Aggregate purchase price           $ 100,000,000  
Amount paid to lender upon entering into agreement           1,000,000  
Amount incurred in securing agreement           $ 1,600,000  
Debt instrument, termination fee   $ 1,500,000