Note 4 - Accounts Receivable and Customer Concentrations - Concentration of Revenue (Details) - Customer Concentration Risk [Member]	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Customer A [Member] | Revenue Benchmark [Member]
Concentration risk	71.00%	69.00%
Customer A [Member] | Accounts Receivable [Member]
Concentration risk	65.00%	59.00%
Customer B [Member] | Revenue Benchmark [Member]
Concentration risk	6.00%	10.00%
Customer B [Member] | Accounts Receivable [Member]
Concentration risk	8.00%	6.00%
Customer C [Member] | Revenue Benchmark [Member]
Concentration risk	1.00%	2.00%
Customer C [Member] | Accounts Receivable [Member]
Concentration risk	0.00%	10.00%