Note 6 - Stockholders' Equity (Deficiency) - Summary of Information Concerning Outstanding and Exercisable Warrants (Details) - $ / shares	9 Months Ended
	Sep. 30, 2018	Dec. 31, 2017	Dec. 31, 2016
Class of warrant or right, exercise price (in dollars per share)	$ 0.52	$ 0.48
Warrants, number outstanding (in shares)	128,600	5,219,163
Warrants Range One [Member]
Class of warrant or right, exercise price (in dollars per share)	$ 0.52
Warrants, number outstanding (in shares)	128,600
Warrants, expiry date	Oct. 26, 2018