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Term Loan - Additional Information (Detail) - Silicon Valley Bank [Member]
12 Months Ended
Dec. 18, 2019
USD ($)
Aug. 31, 2018
USD ($)
Tranches
Dec. 31, 2019
USD ($)
$ / shares
shares
Dec. 31, 2018
USD ($)
Term Loans [Member]        
Debt Instrument [Line Items]        
Aggregate principal amount of loans   $ 15,000,000    
Number of tranches | Tranches   3    
Loan agreement, description     Contemporaneously with executing the Loan Agreement, the Company drew down the first $5.0 million tranche.  
Loan agreement, frequency of payments     monthly  
Interest expense     $ 900,000 $ 200,000
Term loan repaid $ 300,000      
Repayment of term loan 5,000,000      
Term Loans [Member] | Tranche One [Member]        
Debt Instrument [Line Items]        
Aggregate principal amount of loans       $ 5,000,000
Amount borrowed     $ 5,000,000  
Amortization of debt discount and accretion of final payment $ 100,000      
Warrants to Purchase Common Stock [Member]        
Debt Instrument [Line Items]        
Warrant expiration date   Aug. 21, 2028    
Warrants to Purchase Common Stock [Member] | Term Loans [Member]        
Debt Instrument [Line Items]        
Warrants issued in connection with loan | shares     1,839  
Excercise price of warrants or rights | $ / shares     $ 74.80