Note 6 - Stockholders' Equity (Deficiency) - Summary of Information Concerning Outstanding and Exercisable Stock Options (Details)	6 Months Ended
	Jun. 30, 2018 $ / shares shares
Number of outstanding (in shares)	3,635,000
Number of exercisable (in shares)	3,234,500
Range 1 [Member]
Range of exercise prices per share (in dollars per share) | $ / shares	$ 0.42
Number of outstanding (in shares)	855,000
Number of exercisable (in shares)	855,000
Expiry date	Dec. 20, 2021
Range 2 [Member]
Range of exercise prices per share (in dollars per share) | $ / shares	$ 0.42
Number of outstanding (in shares)	650,000
Number of exercisable (in shares)	380,000
Expiry date	Nov. 08, 2022
Range 3 [Member]
Range of exercise prices per share (in dollars per share) | $ / shares	$ 0.42
Number of outstanding (in shares)	855,000
Number of exercisable (in shares)	724,500
Expiry date	Jun. 04, 2023
Range 4 [Member]
Range of exercise prices per share (in dollars per share) | $ / shares	$ 0.50
Number of outstanding (in shares)	1,275,000
Number of exercisable (in shares)	1,275,000
Expiry date	Jun. 04, 2023