Quarterly report pursuant to Section 13 or 15(d)

Note 2 - Revenue (Details Textual)

v3.21.1
Note 2 - Revenue (Details Textual)
$ in Millions
3 Months Ended
Mar. 31, 2021
USD ($)
Mar. 31, 2020
Revenue from Contract with Customers, Sales Returns, Percent 1.00% 2.00%
Contract with Customer, Liability, Revenue Recognized $ 1.1  
Geographic Concentration Risk [Member] | Revenue Benchmark [Member]    
Number of Major Markets 0 0
Customer Concentration Risk [Member] | Revenue Benchmark [Member]    
Number of Major Customers 0 0
Minimum [Member]    
Revenue from Contract with Customer, Sales Returns Policy Term (Day) 14 days  
Revenue from Contract with Customers, Historical Sales Returns, Percent 1.00%  
Maximum [Member]    
Revenue from Contract with Customer, Sales Returns Policy Term (Day) 1 year  
Revenue from Contract with Customers, Historical Sales Returns, Percent 5.00%