Quarterly report pursuant to Section 13 or 15(d)

Net Loss per Share - Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share (Detail)

v3.21.2
Net Loss per Share - Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share (Detail) - shares
 9 Months Ended
Sep. 30, 2021
Sep. 30, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Antidilutive securities excluded from computation of earnings per share, amount 22,170,601 92,607,544
Convertible Preferred Stock (if-converted) [Member]    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Antidilutive securities excluded from computation of earnings per share, amount 0 42,726,773
Warrants For The Purchase Of Series C Convertible Preferred Stock (If-Converted) [Member]    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Antidilutive securities excluded from computation of earnings per share, amount 0 146,919
Warrants For The Purchase Of Common Stock [Member]    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Antidilutive securities excluded from computation of earnings per share, amount 0 1,285,078
Convertible Notes (if-converted) [Member]    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Antidilutive securities excluded from computation of earnings per share, amount 0 34,670,225
Stock Options To Purchase Common Stock [Member]    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Antidilutive securities excluded from computation of earnings per share, amount 22,170,601 13,778,549