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 6 Months Ended
Jul. 16, 2020
shares
Apr. 10, 2020
USD ($)
$ / shares
shares
Sep. 30, 2016
$ / shares
shares
Jun. 30, 2021
USD ($)
$ / shares
shares
Jun. 30, 2020
USD ($)
Jun. 30, 2021
USD ($)
$ / shares
shares
Jun. 30, 2020
USD ($)
May 31, 2021
$ / shares
shares
Dec. 31, 2020
$ / 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)       23,147,552   23,147,552     19,663,698  
Common stock, shares outstanding (in shares)       23,147,552   23,147,552     19,663,698  
Common stock, reverse stock split           1-for-10        
Common stock, reverse stock split ratio 0.1                  
Proceeds from common stock issued | $           $ 3,431,000 $ 2,751,000      
Warrant liabilities fair value adjustment | $       $ 15,271,000 $ 3,560,000 16,567,000 8,329,000      
Warrant liabilities | $       $ 35,000,000.0 $ 51,200,000 $ 35,000,000.0 $ 51,200,000      
Warrants to purchase common stock associated with Loan Agreement                    
Schedule Of Capitalization Equity [Line Items]                    
Number of warrants issued to purchase common stock (in shares)     12,243              
Exercise price of warrants (in dollars per share) | $ / shares     $ 36.754              
Warrant expiration period     5 years              
Warrant | December 2020 Public Offering                    
Schedule Of Capitalization Equity [Line Items]                    
Number of warrants exercised       360,134   2,060,000        
Proceeds from warrant exercised | $       $ 2,600,000   $ 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%                
Aspire Capital | Common Stock Purchase Agreement | Maximum                    
Schedule Of Capitalization Equity [Line Items]                    
Sale of common stock at sole discretion | $   $ 20,000,000.0