Quarterly report pursuant to Section 13 or 15(d)

Borrowing Arrangements - Additional Information (Detail)

v3.20.2
Borrowing Arrangements - Additional Information (Detail) - USD ($)
3 Months Ended 9 Months Ended
May 21, 2020
Feb. 27, 2018
Sep. 30, 2020
Sep. 30, 2019
Sep. 30, 2020
Sep. 30, 2019
Dec. 31, 2019
Debt Instrument [Line Items]              
Loss on extinguishment of debt     $ 0 $ 0 $ (1,237,000) $ 0  
Long-term debt, carrying value     $ 14,800,000   $ 14,800,000   $ 3,700,000
K2 Loan and Security Agreement              
Debt Instrument [Line Items]              
Loan and security agreement $ 45,000.0            
Interest rate     8.45%   8.45%    
Debt net     $ 1,100   $ 1,100    
Total debt     $ 15,000,000.0   $ 15,000,000.0   0.0
Tranche One | K2 Loan and Security Agreement              
Debt Instrument [Line Items]              
Loan and security agreement 15,000.0            
Tranche Two | K2 Loan and Security Agreement              
Debt Instrument [Line Items]              
Loan and security agreement 20,000.0            
Interest rate     0.20%   0.20%    
Tranche Three | K2 Loan and Security Agreement              
Debt Instrument [Line Items]              
Loan and security agreement $ 10,000.0            
Prime Rate | K2 Loan and Security Agreement              
Debt Instrument [Line Items]              
Interest rate     5.20%   5.20%    
Perceptive              
Debt Instrument [Line Items]              
Credit Facility, principal payments         $ 4,900,000    
Credit Facility, interest expense         4,900,000    
Exit fees and prepayment penalties     $ 100,000   100,000    
Loss on extinguishment of debt         (1,200,000)    
Total debt     0.0   $ 0.0   $ 5,000,000.0
Term Loan Facility | Perceptive              
Debt Instrument [Line Items]              
Maximum borrowing capacity under loan   $ 10,000,000.0          
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        
Deferred finance costs   $ 500,000          
Debt issuance cost, net of discount   $ 1,500,000          
Number of shares issued for each warrant   190,000          
Warrant exercisable period   7 years          
Warrant 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   $ 5,000,000.0          
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 did not draw down   $ 5,000,000.0