Note 3 - Inventories (Tables)
 12 Months Ended
Dec. 31, 2019
Notes Tables  
Schedule of Inventory, Current [Table Text Block]
   
December 31, 2019
    
December 31, 2018
  
                 
Raw materials
   $
-
     $
4,346
  
Finished goods
    
7,816
      
5,997
  
     
7,816
      
10,343
  
Reserve for obsolete inventory
    
(1,247
 )    
(2,398
 )
                 
    $
6,569
     $
7,945