Quarterly report pursuant to Section 13 or 15(d)

Note 4 - Stock-based Compensation (Details Textual)

v3.20.2
Note 4 - Stock-based Compensation (Details Textual) - USD ($)
3 Months Ended 6 Months Ended
Jun. 01, 2016
Jun. 30, 2020
Mar. 31, 2020
Jun. 30, 2019
Jun. 30, 2020
Jun. 30, 2019
Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number, Ending Balance (in shares)   1,220,000 1,220,000   1,220,000   1,349,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares)   10,000 3,000 10,000 3,000  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period (in shares)   0 10,000 0 10,000  
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total   $ 775     $ 775    
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Month)         270 days    
Share-based Payment Arrangement, Expense   $ 356   $ 482 $ 806 $ 4,936  
The 2016 Stock Incentive Plan [Member]              
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares) 1,000,000            
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year) 10 years            
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number, Ending Balance (in shares)   381,000     381,000    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number (in shares)   368,000     368,000    
The 2006 Stock Incentive Plan [Member]              
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares)   1,950,000     1,950,000    
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year)         10 years    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number (in shares)   839,000     839,000    
Minimum [Member] | Share-based Payment Arrangement, Option [Member]              
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Month)         180 days    
Maximum [Member] | Share-based Payment Arrangement, Option [Member]              
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Month)         2 years