Annual report pursuant to Section 13 and 15(d)

Note 10 - Stock Options and Warrants (Details Textual)

v3.20.1
Note 10 - Stock Options and Warrants (Details Textual) - USD ($)
12 Months Ended
Jun. 01, 2016
Dec. 31, 2019
Dec. 31, 2018
May 18, 2006
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number, Ending Balance   1,349,000 1,376,500  
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total   $ 781    
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition   90 days    
The 2016 Stock Incentive Plan [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized 1,000,000      
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period 10 years      
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number, Ending Balance   371,000 373,000  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number   347,500 224,500  
The 2006 Stock Incentive Plan [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized       1,950,000
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period   10 years    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number   978,000 1,003,500  
Minimum [Member] | Share-based Payment Arrangement, Option [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period   180 days    
Maximum [Member] | Share-based Payment Arrangement, Option [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period   2 years