XML 70 R57.htm IDEA: XBRL DOCUMENT v3.21.2
NET LOSS PER SHARE - Antidilutive securities (Details) - shares
6 Months Ended
Jun. 30, 2021
Jun. 30, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Potentially dilutive shares (in shares) 23,166,935 26,901,491
Convertible promissory notes    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Potentially dilutive shares (in shares) 0 7,473,946
Outstanding stock options    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Potentially dilutive shares (in shares) 10,357,133 9,585,364
Outstanding warrants    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Potentially dilutive shares (in shares) 12,809,802 9,842,181