Note 11 - Capital Stock - Continuity Schedule of Outstanding Share Purchase Warrants (Details)	6 Months Ended
	Jan. 31, 2019 $ / shares shares
Balance, July 31, 2018 (in shares) | shares	30,923,489
Balance, July 31, 2018 (in dollars per share) | $ / shares	$ 1.97
Issued (in shares) | shares	7,063,253
Issued (in dollars per share) | $ / shares	$ 2.05
Exercised (in shares) | shares	(2,061,764)
Exercised (in dollars per share) | $ / shares	$ 1.21
Expired (in shares) | shares	(2,850,000)
Expired (in dollars per share) | $ / shares	$ 2.35
Balance, January 31, 2019 (in shares) | shares	33,074,978
Balance, January 31, 2019 (in dollars per share) | $ / shares	$ 2