Annual report pursuant to Section 13 and 15(d)

Stockholders' Equity (Schedule of Warrant activities) (Details)

v3.21.1
Stockholders' Equity (Schedule of Warrant activities) (Details) - USD ($)
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Equity [Abstract]      
Warrants outstanding, Number of shares 2,741,180 2,754,189  
Warrants granted, Number of shares 1,849,450 60,000  
Warrants forfeited, Number of shares (9) (73,009)  
Warrants outstanding, Number of shares 4,590,621 2,741,180 2,754,189
Warrants exercisable, Number of shares 4,430,621    
Warrants outstanding, Weighted average exercise price $ 3.19 $ 3.28  
Warrants granted, Weighted average exercise price 3.14 1.92  
Warrants forfeited, Weighted average exercise price 3.00 5.65  
Warrants outstanding, Weighted average exercise price 3.17 $ 3.19 $ 3.28
Warrants exercisable, Weighted average exercise price $ 3.21    
Warrants outstanding, Weighted average intrinsic value $ 111,000 $ 0  
Warrants granted, Weighted average intrinsic value 101,000 39,000  
Warrants forfeited, Weighted average intrinsic value 2 0  
Warrants outstanding, Weighted average intrinsic value 607,848 $ 111,000 $ 0
Warrants exercisable, Weighted average intrinsic value $ 452,848    
Warrants, Weighted average remaining contractual life 4 years 10 months 6 days 2 years 8 months 23 days 3 years 5 months 26 days
Warrants exercisable, Weighted average remaining contractual life 4 years 9 months 18 days