General form of registration statement for all companies including face-amount certificate companies

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
 6 Months Ended 12 Months Ended
Jun. 30, 2021
Jun. 30, 2020
Dec. 31, 2020
Dec. 31, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]        
Antidilutive securities excluded from computation of earnings per share, amount 60,655,159 53,296,805 57,322,164 53,502,731
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 25,134,067 25,047,938 25,047,938 25,047,938
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 86,129 86,129 86,129
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 1,397,173 298,459 1,364,761 266,047
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 21,704,588 20,324,906 20,060,646 19,820,736
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 12,419,331 7,539,373 10,762,690 8,281,881