Note 11 - Major Customers and Accounts Receivable (Details Textual) - Customer Concentration Risk [Member]	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Revenue Benchmark [Member] | Customer 1 [Member]
Concentration Risk, Percentage	18.00%	0.00%	13.00%	14.00%
Revenue Benchmark [Member] | Customer 2 [Member]
Concentration Risk, Percentage	16.00%	1.00%	11.00%	1.00%
Revenue Benchmark [Member] | Customer 3 [Member]
Concentration Risk, Percentage	11.00%	25.00%		30.00%
Revenue Benchmark [Member] | Customer 4 [Member]
Concentration Risk, Percentage	0.00%	18.00%
Accounts Receivable [Member]
Number of Major Customers			4		3
Accounts Receivable [Member] | Four Customers [Member]
Concentration Risk, Percentage			68.00%
Accounts Receivable [Member] | Three Customers [Member]
Concentration Risk, Percentage					72.00%