Note 1 - Organization and Significant Accounting Policies (Tables)
 3 Months Ended
Mar. 31, 2020
Notes Tables  
Revenue from External Customers by Products and Services [Table Text Block]
   
Three Months Ended March 31,
  
Revenue by customers’ geographic locations
  
2020
    
2019
  
United States
    
74
%
    
60
%
Canada
    
11
%
    
23
%
Europe, Middle East, Africa (EMEA)
    
12
%
    
13
%
Other
    
3
%
    
4
%
Total revenue
    
100
%
    
100
%