Note 15 - Significant Customers - Customers Concentration Summary (Details) - Customer Concentration Risk [Member]	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Distributor A [Member] | Revenue Benchmark [Member]
Concentration risk	23.00%	22.00%	17.00%
Distributor A [Member] | Accounts Receivable [Member]
Concentration risk	24.00%	25.00%
Distributor B [Member] | Revenue Benchmark [Member]
Concentration risk		10.00%
Distributor B [Member] | Accounts Receivable [Member]
Concentration risk	11.00%	16.00%
Distributor C [Member] | Revenue Benchmark [Member]
Concentration risk			10.00%
Value Added Reseller A [Member] | Accounts Receivable [Member]
Concentration risk	13.00%