Annual report pursuant to Section 13 and 15(d)

Stock Option Plans - Assumptions Used To Compute The Fair Value Of Stock Options (Details)

v3.20.1
Stock Option Plans - Assumptions Used To Compute The Fair Value Of Stock Options (Details) - USD ($)
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Value of options granted:      
Number of options granted 73,500 330,500 534,500
Weighted average fair value per share $ 1.71 $ 5.01 $ 5.24
Fair value of options issued $ 125,814 $ 1,655,390 $ 2,803,329
Minimum [Member]      
Assumptions for Black-Scholes:      
Expected term in years 6 years 2 months 12 days 6 years 6 months 6 years 6 months
Volatility 79.40% 108.90% 122.80%
Risk-free interest rate 1.63% 2.95% 1.98%
Maximum [Member]      
Assumptions for Black-Scholes:      
Expected term in years 6 years 3 months 18 days 6 years 6 months 6 years 9 months 18 days
Volatility 89.40% 119.40% 133.00%
Risk-free interest rate 1.68% 3.08% 2.30%