Quarterly report pursuant to Section 13 or 15(d)

Borrowing Arrangements - Additional Information (Detail)

v3.19.1
Borrowing Arrangements - Additional Information (Detail) - USD ($)
3 Months Ended
Feb. 27, 2018
Mar. 31, 2019
Mar. 31, 2018
Dec. 31, 2018
Debt Instrument [Line Items]        
Credit facility, amortization of debt discount   $ 105,000 $ 63,000  
Perceptive        
Debt Instrument [Line Items]        
Debt instrument, annual interest rate   13.80%    
Credit Facility, final payments $ 3,400,000      
Credit Facility, interest expense   $ 172,000 59,000  
Credit facility, amortization of debt discount   74,000 $ 54,000  
Total debt   $ 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