Stockholders' Equity (Deficit) - Additional Information (Detail)
 6 Months Ended 12 Months Ended
Oct. 26, 2021
USD ($)
$ / shares
shares
Oct. 12, 2021
USD ($)
$ / shares
shares
May 24, 2021
USD ($)
shares
May 20, 2021
USD ($)
$ / shares
shares
Apr. 06, 2021
USD ($)
Mar. 29, 2021
USD ($)
$ / shares
shares
Jun. 10, 2020
USD ($)
shares
Jun. 05, 2020
USD ($)
$ / shares
shares
Jun. 30, 2021
USD ($)
$ / shares
shares
Dec. 31, 2021
USD ($)
$ / shares
shares
Dec. 31, 2020
USD ($)
$ / shares
shares
Mar. 01, 2022
$ / shares
shares
Jan. 13, 2022
$ / shares
shares
Dec. 15, 2021
$ / shares
shares
May 31, 2021
$ / shares
shares
Nov. 30, 2019
USD ($)
Jan. 17, 2018
$ / shares
shares
Class Of Stock [Line Items]                                  
Stock option warrant to purchase, exercise price per share (in dollars per share)                   $ 1.54              
Preferred stock par value (in dollars per share)                           $ 0.0001      
Proceeds from issuance of common stock and warrants | $                 $ 81,500,000                
Convertible preferred stock, discount accretion period                   4 years              
Convertible preferred stock issued, net of offering expense | $                   $ 9,600,000              
Convertible preferred stock issued, discount | $                   500,000              
Convertible preferred stock, deemed dividend, return of capital | $                   $ 800,000              
Issuance and sale of an aggregate shares (in shares) | shares                   5,000,000 5,000,000     5,000,000      
Common stock, shares authorized (in shares) | shares                   500,000,000 500,000,000     500,000,000     300,000,000
Common stock, par value (in dollars per share)                   $ 0.0001 $ 0.0001           $ 0.0001
Proceeds from issuance of common stock | $                   $ 0 $ 3,781,000            
Subsequent Event                                  
Class Of Stock [Line Items]                                  
Number of shares of to purchase capital stock (in shares) | shares                       15,568,287 15,006,003        
Stock option warrant to purchase, exercise price per share (in dollars per share)                       $ 0.4787 $ 0.392        
Common stock, par value (in dollars per share)                       $ 0.0001 0.0001        
Series B1 Convertible Preferred Stock                                  
Class Of Stock [Line Items]                                  
Conversion price (in dollars per share)   $ 0.63                              
Common Stock                                  
Class Of Stock [Line Items]                                  
Stock issued during period (in shares) | shares   7,936,508                              
Convertible Preferred Stock                                  
Class Of Stock [Line Items]                                  
Derivative liability | $                   500,000              
Convertible preferred stock, deemed dividend, accretion | $                   300,000              
Gain on financial instrument | $                   $ 100,000              
Public Offering                                  
Class Of Stock [Line Items]                                  
Number of shares of to purchase capital stock (in shares) | shares       50,000,000                          
Stock option warrant to purchase, exercise price per share (in dollars per share)       $ 1.00                          
Number of shares issued (in shares) | shares       50,000,000   17,142,857   28,500,000                  
Price per share (in dollars per share)       $ 1.00   $ 1.75   $ 3.50                  
Proceeds from issuance of common stock and warrants | $           $ 28,000,000   $ 93,200,000                  
Period to purchase common stock at the public offering price               30 days                  
Number of shares of common stock available for purchase at public offering price (in shares) | shares               4,275,000                  
Proceeds from public offering | $       $ 46,800,000                          
Registered Direct Offering | Series B1 Convertible Preferred Stock                                  
Class Of Stock [Line Items]                                  
Number of shares issued (in shares) | shares   5,000                              
Preferred stock par value (in dollars per share)   $ 0.0001                              
Price per share (in dollars per share)   $ 1,000                              
Proceeds from issuance of common stock and warrants | $   $ 4,600,000                              
Conversion price calculation, multiplier of average closing stock price for a specified period   0.85                              
Threshold consecutive trading days   5 days                              
Converted shares (in shares) | shares   5,000                              
Registered Direct Offering | Series B1 Convertible Preferred Stock | Minimum                                  
Class Of Stock [Line Items]                                  
Conversion price per share (in dollars per share) $ 0.60                                
Registered Direct Offering | Series B-2 convertible preferred stock                                  
Class Of Stock [Line Items]                                  
Number of shares issued (in shares) | shares 5,000                                
Preferred stock par value (in dollars per share) $ 0.0001                                
Price per share (in dollars per share) $ 1,000                                
Proceeds from issuance of common stock and warrants | $ $ 5,000,000                                
Conversion price calculation, multiplier of average closing stock price for a specified period 0.85                                
Threshold consecutive trading days 5 days                                
Registered Direct Offering | Series B-2 convertible preferred stock | Minimum                                  
Class Of Stock [Line Items]                                  
Conversion price per share (in dollars per share) $ 0.60                                
Registered Direct Offering | Series B-2 convertible preferred stock | Subsequent Event | Minimum                                  
Class Of Stock [Line Items]                                  
Conversion price per share (in dollars per share)                         $ 0.392        
Over-allotment option                                  
Class Of Stock [Line Items]                                  
Number of shares of to purchase capital stock (in shares) | shares       7,500,000                          
Stock option warrant to purchase, exercise price per share (in dollars per share)       $ 0.01                          
Number of shares issued (in shares) | shares     2,547,794       3,200,000                    
Price per share (in dollars per share)       $ 0.99                          
Proceeds from issuance of common stock and warrants | $     $ 2,400,000   $ 4,200,000   $ 10,500,000                    
Period to purchase common stock at the public offering price       30 days   30 days                      
Number of shares of common stock available for purchase at public offering price (in shares) | shares       7,500,000   2,571,428                      
Proceeds from issuance of warrants | $       $ 100,000                          
ATM | Piper Sandler & Co.                                  
Class Of Stock [Line Items]                                  
Number of shares issued (in shares) | shares                     676,656            
Offering price of shares | $                               $ 50,000,000  
Proceeds from issuance of common stock | $                     $ 3,800,000            
Security Purchase Agreement Warrants                                  
Class Of Stock [Line Items]                                  
Number of shares of to purchase capital stock (in shares) | shares                 5,122,950                
Stock option warrant to purchase, exercise price per share (in dollars per share)                 $ 2.44                
Warrants                                  
Class Of Stock [Line Items]                                  
Shares issued upon exercise (in shares) | shares                   159,000              
Warrants | Public Offering                                  
Class Of Stock [Line Items]                                  
Number of shares of to purchase capital stock (in shares) | shares                             57,500,000    
Stock option warrant to purchase, exercise price per share (in dollars per share)                             $ 1.00