Note 12 - Subsequent Events (Details Textual) - $ / shares	1 Months Ended	6 Months Ended	12 Months Ended
	Jul. 31, 2018	Jun. 30, 2018	Dec. 31, 2017
Shares Issued, Price Per Share		$ 0.04
Class of Warrant or Right, Number of Securities Called by Warrants or Rights		24,813,373	18,813,373
Class of Warrant or Right, Exercise Price of Warrants or Rights		$ 0.15	$ 0.14
Subsequent Event [Member] | Investor Warrants [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights	1,875,000
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 0.15
Private Placement [Member]
Stock Issued During Period, Shares, New Issues		8,000,000	26,500,000
Shares Issued, Price Per Share		$ 0.15
Class of Warrant or Right, Exercise Price of Warrants or Rights		$ 0.08	$ 0.04
Private Placement [Member] | Subsequent Event [Member]
Stock Issued During Period, Shares, New Issues	1,875,000
Shares Issued, Price Per Share	$ 0.08