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

Net Loss Per Share - Summary Of Diluted Shares Outstanding (Detail)

v3.21.2
Net Loss Per Share - Summary Of Diluted Shares Outstanding (Detail) - shares
 9 Months Ended 12 Months Ended
Sep. 30, 2021
Sep. 30, 2020
Dec. 31, 2020
Dec. 31, 2019
Series C Convertible Preferred Stock [Member]        
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]        
Antidilutive Securities Excluded from Computation of EPS 0 2,566,186 2,566,186 2,566,186
Stock Option [Member]        
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]        
Antidilutive Securities Excluded from Computation of EPS 0 432,500 432,500 399,151