Note 2 - Liquidity and Summary of Significant Accounting Principles - Summary of Concentration Risk (Details) - Customer Concentration Risk [Member]	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Accounts Receivable [Member] | Customer A [Member]
Concentration percentage					58.00%
Accounts Receivable [Member] | Customer B [Member]
Concentration percentage					29.00%
Revenue Benchmark [Member] | Customer A [Member]
Concentration percentage	78.00%		52.00%
Revenue Benchmark [Member] | Customer C [Member]
Concentration percentage		75.00%		52.00%
Revenue Benchmark [Member] | Customer D [Member]
Concentration percentage			13.00%
Revenue Benchmark [Member] | Customer E [Member]
Concentration percentage			12.00%
Revenue Benchmark [Member] | Customer F [Member]
Concentration percentage			11.00%