Note 15 - Concentrations of Credit Risk (Details Textual)	3 Months Ended	12 Months Ended
	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Cash and Cash Equivalents, Including Long-term Cash Equivalents	$ 580,794	$ 1,005,624
Cash, Uninsured Amount	$ 369,553	$ 661,741
Customer Concentration Risk [Member] | Accounts Receivable [Member]
Number of Major Customers	1	1
Accounts Receivable, after Allowance for Credit Loss, Total	$ 1,207,506	$ 1,430,646