Annual report pursuant to Section 13 and 15(d)

Borrowing Arrangements - Additional Information (Detail)

v3.19.1
Borrowing Arrangements - Additional Information (Detail)
 1 Months Ended 12 Months Ended
Feb. 27, 2018
USD ($)
$ / shares
shares
Apr. 30, 2016
USD ($)
$ / shares
shares
Jun. 30, 2015
USD ($)
$ / shares
shares
May 31, 2015
USD ($)
Dec. 31, 2018
USD ($)
Dec. 31, 2017
USD ($)
Installment
Apr. 30, 2015
USD ($)
shares
Debt Instrument [Line Items]              
Credit facility, amortization of debt discount         $ 318,000 $ 342,000  
Perceptive              
Debt Instrument [Line Items]              
Final fee due at loan maturity date $ 3,400,000            
Debt instrument, annual interest rate         13.80%    
Total debt         $ 5,000,000 0  
Credit Facility, interest expense         569,000 $ 0  
Credit facility, amortization of debt discount         $ 292,000    
Term Loan Facility | Perceptive              
Debt Instrument [Line Items]              
Maximum borrowing capacity under loan $ 10,000,000            
Common stock exercise price | $ / shares $ 9.5792            
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 | shares 190,000            
Fair value of the warrant recorded as a debt discount $ 1,500,000            
Warrant exercisable period 7 years            
LIBOR | Term Loan Facility | Perceptive              
Debt Instrument [Line Items]              
Debt instrument, basis spread on variable rate 11.00%            
SVB Growth Capital Loan              
Debt Instrument [Line Items]              
Debt instrument, frequency of periodic payment         3 30  
Maximum borrowing capacity under loan             $ 6,000,000
Number of warrants to purchase shares of common stock | shares   17,310 14,254       48,874
Final fee due at loan maturity date             $ 375,000
Amount drew down from bank   $ 3,000,000 $ 2,300,000 $ 800,000      
Common stock exercise price | $ / shares   $ 3.07 $ 3.07        
Aggregate amount drawn down from credit facility           $ 6,000,000  
Debt instrument first installment due date           Nov. 01, 2016  
Debt instrument maturity date           Apr. 30, 2019  
Debt instrument, annual interest rate           5.44%  
Number of frequency of consecutive equal monthly payments of principal plus interest paid | Installment           30  
Debt instrument principal paid during period         $ 3,200,000 $ 2,400,000  
Debt instrument interest paid during period         42,000 237,000  
Final fee paid         375,000    
Total debt         $ 0 $ 3,500,000  
SVB Growth Capital Loan | Prime Rate              
Debt Instrument [Line Items]              
Debt instrument, basis spread on variable rate           1.19%  
Term Loan Drawn on Effective Date of Credit Facility | Term Loan Facility | Perceptive              
Debt Instrument [Line Items]              
Proceeds from initial term loan on closing date of Credit Facility $ 5,000,000            
Additional Term Loan Drawn Six Months Following Effective Date of Credit Facility | Term Loan Facility | Perceptive              
Debt Instrument [Line Items]              
Remaining available amount from credit facility to be drawn six months following effective date of credit facility $ 5,000,000