Note 15 - Significant Customers - Customers Concentration Summary (Details) - Customer Concentration Risk [Member]	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue Benchmark [Member]
Concentration Risk, Percentage	81.00%	83.00%	87.00%
Revenue Benchmark [Member] | Distributor A [Member]
Concentration Risk, Percentage	24.00%	23.00%	22.00%
Revenue Benchmark [Member] | Distributor B [Member]
Concentration Risk, Percentage	11.00%		10.00%
Accounts Receivable [Member] | Distributor A [Member]
Concentration Risk, Percentage	24.00%	24.00%
Accounts Receivable [Member] | Distributor B [Member]
Concentration Risk, Percentage	21.00%	11.00%
Accounts Receivable [Member] | Value Added Reseller A [Member]
Concentration Risk, Percentage	13.00%	13.00%
Accounts Receivable [Member] | Customer A (Direct) [Member]
Concentration Risk, Percentage	10.00%