Note 8 - Stockholders' Deficiency - Summary of Warrant Activity (Details)	12 Months Ended
	Dec. 31, 2017 $ / shares shares
Outstanding (in shares) | shares
Outstanding (in shares) | shares	5,219,163
Outstanding, exercise price (in dollars per share)	$ 0.48
Warrants with June 15, 2018 Expiration Date [Member]
Granted (in shares) | shares	2,323,779
Granted, expiry date	Jun. 15, 2018
Exercised (in shares) | shares	(121,111)
Exercised, exercise price (in dollars per share)	$ (0.43)
Exercised, expiry date	Jun. 15, 2018
Warrants with June 15, 2018 Expiration Date [Member] | Minimum [Member]
Granted, exercise price (in dollars per share)	$ 0.43
Warrants with June 15, 2018 Expiration Date [Member] | Maximum [Member]
Granted, exercise price (in dollars per share)	$ 0.49
Warrants with September 28, 2018 Expiration Date [Member]
Granted (in shares) | shares	2,887,895
Granted, expiry date	Sep. 28, 2018
Warrants with September 28, 2018 Expiration Date [Member] | Minimum [Member]
Granted, exercise price (in dollars per share)	$ 0.44
Warrants with September 28, 2018 Expiration Date [Member] | Maximum [Member]
Granted, exercise price (in dollars per share)	$ 0.52
Warrants with October 26, 2018 Expiration Date [Member]
Granted (in shares) | shares	128,600
Granted, expiry date	Oct. 26, 2018
Warrants with October 26, 2018 Expiration Date [Member] | Minimum [Member]
Granted, exercise price (in dollars per share)	$ 0.44
Warrants with October 26, 2018 Expiration Date [Member] | Maximum [Member]
Granted, exercise price (in dollars per share)	$ 0.52