Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity - Additional Information (Detail)

v3.21.2
Stockholders' Equity - Additional Information (Detail)
3 Months Ended 9 Months Ended
Jul. 16, 2020
shares
Apr. 10, 2020
USD ($)
$ / shares
shares
Sep. 30, 2021
USD ($)
$ / shares
shares
Sep. 30, 2020
USD ($)
Sep. 30, 2021
USD ($)
$ / shares
shares
Sep. 30, 2020
USD ($)
shares
May 31, 2021
$ / shares
shares
Dec. 31, 2020
USD ($)
$ / shares
shares
Jul. 17, 2020
shares
Schedule Of Capitalization Equity [Line Items]                  
Common stock, par value (in dollars per share) | $ / shares     $ 0.001   $ 0.001     $ 0.001  
Common stock, shares authorized (in shares) 250,000,000   100,000,000   100,000,000     100,000,000 100,000,000
Common stock, shares issued (in shares)     23,885,570   23,885,570     19,663,698  
Common stock, shares outstanding (in shares)     23,885,570   23,885,570     19,663,698  
Common stock, reverse stock split         1-for-10        
Common stock, reverse stock split ratio 0.1                
Proceeds from common stock issued | $         $ 8,027,000 $ 4,702,000      
Warrant liabilities fair value adjustment | $     $ 18,810,000 $ 7,786,000 35,378,000 $ 16,114,000      
Warrant liabilities | $     $ 15,300,000   $ 15,300,000     $ 51,200,000  
December 2020 Public Offering Warrants                  
Schedule Of Capitalization Equity [Line Items]                  
Number of warrants exercised         360,134        
Proceeds from warrant exercised | $         $ 2,600,000        
Pre-funded Warrants                  
Schedule Of Capitalization Equity [Line Items]                  
Number of warrants exercised         2,060,000        
Proceeds from warrant exercised | $         $ 2,000        
Loan and Security Agreement | Hercules Capital Inc. and Silicon Valley Bank                  
Schedule Of Capitalization Equity [Line Items]                  
Common stock, par value (in dollars per share) | $ / shares             $ 0.001    
Multiplier value by aggregate amount of the term loan advances divided by exercise price of warrants to calculate number of shares for purchase             0.04    
Number of warrants issued to purchase common stock (in shares)             113,607    
Aspire Capital | Common Stock Purchase Agreement                  
Schedule Of Capitalization Equity [Line Items]                  
Number of purchase aggregate shares of common stock   1,956,547              
Percentage of common stock outstanding   19.99%              
Number of shares committed   70,910              
Average purchase price of shares sold | $ / shares   $ 8.461              
Percentage of common stock owned   19.99%              
Common stock issued, net of expenses (in shares)         400,000 125,000      
Proceeds from common stock issued | $         $ 2,600,000 $ 600,000      
Aspire Capital | Common Stock Purchase Agreement | Maximum                  
Schedule Of Capitalization Equity [Line Items]                  
Sale of common stock at sole discretion | $   $ 20,000,000.0              
Cantor Fitzgerald & Co. and Ladenburg Thalmann & Co. Inc. | Sales Agreement                  
Schedule Of Capitalization Equity [Line Items]                  
Common stock issued, net of expenses (in shares)         430,605        
Proceeds from common stock issued | $         $ 2,500,000