Quarterly report pursuant to Section 13 or 15(d)

Note 3 - Summary of Significant Accounting Policies (Details Textual)

v3.19.2
Note 3 - Summary of Significant Accounting Policies (Details Textual)
6 Months Ended 12 Months Ended
Jun. 30, 2019
USD ($)
shares
Jun. 30, 2018
USD ($)
Dec. 31, 2018
USD ($)
shares
Jan. 01, 2019
USD ($)
Number of Operating Segments 2      
Accounts Receivable, Allowance for Credit Loss, Ending Balance $ 10,000   $ 10,000  
Inventory Valuation Reserves, Ending Balance 754,000   763,000  
Unrecognized Tax Benefits, Ending Balance 0   0  
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense, Total $ 0 $ 0    
Open Tax Year 2015 2016 2017      
Operating Lease, Right-of-Use Asset $ 92,830   $ 166,292
Operating Lease, Liability, Total $ 92,830     $ 166,292
Options and Warrants [Member]        
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount | shares 5,053,832   6,703,553  
Minimum [Member]        
Property, Plant and Equipment, Useful Life 2 years      
Maximum [Member]        
Property, Plant and Equipment, Useful Life 7 years