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

CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY - Common Stock to Employees (Details)

v3.20.4
CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY - Common Stock to Employees (Details) - Employee - $ / shares
9 Months Ended 12 Months Ended
Sep. 30, 2020
Sep. 30, 2019
Dec. 31, 2019
Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Risk-free interest rate, Minimum 0.30% 1.90% 1.70% 2.70%
Risk-free interest rate, Maximum 1.70% 2.60% 2.60% 3.00%
Expected volatility, Minimum 52.70% 53.30% 52.70% 52.90%
Expected volatility, Maximum 54.20% 53.60% 53.60% 53.80%
Expected life, Minimum (in years) 5 years 10 months 24 days 5 years 7 months 6 days 5 years 7 months 6 days 5 years 3 months 18 days
Expected life, Maximum (in years) 6 years 3 months 18 days 6 years 1 month 6 days 6 years 1 month 6 days 6 years 1 month 6 days
Fair value of Common Stock   $ 4.08 $ 4.08 $ 3.39
Minimum        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Fair value of Common Stock $ 1.71      
Maximum        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Fair value of Common Stock $ 9.75