Note 12 - Subsequent Events (Details Textual) - USD ($)	1 Months Ended	6 Months Ended
	Feb. 06, 2020	Dec. 31, 2019	Dec. 31, 2018
Sale of Units, Value		$ 977,000	$ 477,365
Subsequent Event [Member] | Sale of Units, One [Member]
Shares Issued, Price Per Share	$ 0.50
Sale of Units, Value	$ 25,000
Number of Shares Per Unit	1
Number of Warrants Per Unit	0.5
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 0.75