XML 23 R31.htm IDEA: XBRL DOCUMENT v3.20.1
Note 8 - Warrants (Tables)
3 Months Ended
Mar. 31, 2020
Notes Tables  
Schedule of Stockholders' Equity Note, Warrants or Rights [Table Text Block]
   
Shares
   
Wtd. Avg.
Exercise
Price
 
Outstanding at December 31, 2019
   
3,959,005
    $
4.33
 
Exercised
   
(2,000
)
   
4.75
 
Outstanding at March 31, 2020
   
3,957,005
    $
4.33