Annual report pursuant to Section 13 and 15(d)

Note 11 - Share-based Compensation - Summary of Stock Option and Inducement Stock Option Activity (Details)

v3.19.1
Note 11 - Share-based Compensation - Summary of Stock Option and Inducement Stock Option Activity (Details) - USD ($)
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Inducement Stock Options [Member]      
Outstanding, number of authorized shares (in shares) [1] 800,000  
Outstanding, weighted average exercise price (in dollars per share)   $ 2.25  
Outstanding, weighted average remaining contractual term (Year) 5 years 153 days   2 years 94 days
Outstanding, aggregate intrinsic value $ 111,250 $ 240,000
Granted, number of authorized shares (in shares) [1] 125,000  
Granted, weighted average exercise price (in dollars per share) $ 2.55  
Exercised, number of authorized shares (in shares) [1]  
Forfeited, number of authorized shares (in shares) [1] (800,000)  
Outstanding, number of authorized shares (in shares) [1] 125,000 800,000
Outstanding, weighted average exercise price (in dollars per share) $ 2.55   $ 2.25
Exercisable, number of authorized shares (in shares) [1]    
Exercisable, weighted average exercise price (in dollars per share)    
Granted, weighted average remaining contractual term (Year) 5 years 153 days    
Granted, aggregate intrinsic value $ 111,250    
2007 Stock Incentive Plan [Member]      
Outstanding, number of authorized shares (in shares) 133,332 488,332  
Outstanding, weighted average exercise price (in dollars per share) $ 1.99 $ 2.31  
Outstanding, weighted average remaining contractual term (Year)     91 days
Outstanding, aggregate intrinsic value $ 40,716 $ 118,899
Granted, number of authorized shares (in shares)    
Granted, weighted average exercise price (in dollars per share)    
Exercised, number of authorized shares (in shares) (33,576) (25,037)  
Exercised, weighted average exercise price (in dollars per share) $ 1.96 $ 1.51  
Exercised, aggregate intrinsic value $ 162,134 $ 86,900  
Exercised shares forgone to satisfy minimum statutory withholding, number of authorized shares (in shares) (14,255) (13,245)  
Exercised shares forgone to satisfy minimum statutory withholding, weighted average exercise price (in dollars per share) $ 1.96 $ 2.32  
Cashless exercise, number of authorized shares (in shares) 65,501 (71,718)  
Cashless exercise, weighted average exercise price (in dollars per share) $ 1.96 $ 2.32  
Forfeited, number of authorized shares (in shares) (20,000) (245,000)  
Forfeited, weighted average exercise price (in dollars per share) $ 1.93 $ 2.83  
Cashless exercise, number of authorized shares (in shares) (65,501) 71,718  
Outstanding, number of authorized shares (in shares) 133,332 488,332
Outstanding, weighted average exercise price (in dollars per share) $ 1.99 $ 2.31
Exercisable, number of authorized shares (in shares)    
Exercisable, weighted average exercise price (in dollars per share)    
2014 Amended and Restated Stock Incentive Plan [Member]      
Outstanding, number of authorized shares (in shares) 1,962,500 1,249,999  
Outstanding, weighted average exercise price (in dollars per share) $ 2.44 $ 2.80  
Outstanding, weighted average remaining contractual term (Year) 3 years 3 days 3 years 65 days 4 years 94 days
Outstanding, aggregate intrinsic value $ 1,719,584
Granted, number of authorized shares (in shares) 825,000 1,087,500  
Granted, weighted average exercise price (in dollars per share) $ 3.14 $ 2.09  
Exercised, number of authorized shares (in shares) (10,953)  
Exercised, weighted average exercise price (in dollars per share) $ 2.15  
Exercised, aggregate intrinsic value $ 12,159    
Exercised shares forgone to satisfy minimum statutory withholding, number of authorized shares (in shares) (5,134)  
Exercised shares forgone to satisfy minimum statutory withholding, weighted average exercise price (in dollars per share) $ 2.15  
Cashless exercise, number of authorized shares (in shares) 33,079  
Cashless exercise, weighted average exercise price (in dollars per share) $ 2.15  
Forfeited, number of authorized shares (in shares) (514,167) (374,999)  
Forfeited, weighted average exercise price (in dollars per share) $ 2.62 $ 2.61  
Cashless exercise, number of authorized shares (in shares) (33,079)  
Outstanding, number of authorized shares (in shares) 2,224,167 1,962,500 1,249,999
Outstanding, weighted average exercise price (in dollars per share) $ 2.67 $ 2.44 $ 2.80
Exercisable, number of authorized shares (in shares)   955,868  
Exercisable, weighted average exercise price (in dollars per share)   $ 2.69  
Granted, weighted average remaining contractual term (Year) 3 years 233 days 3 years 47 days  
2014 Amended and Restated Stock Incentive Plan [Member] | 2007 Plan (Options) [Member]      
Exercisable, number of authorized shares (in shares) 1,101,910    
Exercisable, weighted average exercise price (in dollars per share) $ 2.52    
[1] Represents inducement stock options to purchase shares of the Company's Common Stock to executive level managers.