Quarterly report pursuant to Section 13 or 15(d)

Borrowing Arrangements - Additional Information (Detail)

v3.19.2
Borrowing Arrangements - Additional Information (Detail) - USD ($)
3 Months Ended 6 Months Ended
Feb. 27, 2018
Jun. 30, 2019
Jun. 30, 2018
Jun. 30, 2019
Jun. 30, 2018
Dec. 31, 2018
Debt Instrument [Line Items]            
Credit facility, amortization of debt discount       $ 221,000 $ 127,000  
Perceptive            
Debt Instrument [Line Items]            
Debt instrument, annual interest rate   13.32%   13.32%    
Credit Facility, final payments $ 3,400,000          
Credit Facility, interest expense   $ 172,000 $ 168,000 $ 344,000 228,000  
Credit facility, amortization of debt discount   82,000 $ 59,000 156,000 $ 81,000  
Total debt   $ 5,000,000   $ 5,000,000   $ 5,000,000
Term Loan Facility | Perceptive            
Debt Instrument [Line Items]            
Maximum borrowing capacity under Credit Facility $ 10,000,000          
Increase in applicable margin percentage on event of default 4.00%          
Period for which interest only payments will be made 24 months          
Credit Facility, principal payments $ 200,000          
Credit Facility, maturity date Feb. 27, 2022          
Exit fee $ 100,000          
Number of shares issued for each warrant 190,000          
Warrant exercisable period 7 years          
Common stock exercise price $ 9.5792          
Fair value of the warrant recorded as a debt discount $ 1,500,000          
Term Loan Facility | Perceptive | LIBOR            
Debt Instrument [Line Items]            
Applicable margin percentage 11.00%          
Term Loan Facility | Perceptive | Term Loan Drawn on Effective Date of Credit Facility            
Debt Instrument [Line Items]            
Proceeds from initial term loan on closing date of Credit Facility $ 5,000,000          
Term Loan Facility | Perceptive | Additional Term Loan Drawn Six Months Following Effective Date of Credit Facility            
Debt Instrument [Line Items]            
Remaining available amount from credit facility to be drawn six months following effective date of credit facility $ 5,000,000