Note 12 - Capital Stock - Continuity Schedule of Outstanding Share Purchase Warrants (Details)	6 Months Ended
	Jan. 31, 2020 $ / shares shares
Balance, Number of Warrants (in shares) | shares	19,443,910
Balance, Weighted Average Exercise Price (in dollars per share) | $ / shares	$ 1.94
Issued, Number of Warrants (in shares) | shares	300,000
Issued, Weighted Average Exercise Price (in dollars per share) | $ / shares	$ 1.38
Expired, Number of Warrants (in shares) | shares	(12,021,929)
Expired, Weighted Average Exercise Price (in dollars per share) | $ / shares	$ 1.87
Balance, Number of Warrants (in shares) | shares	7,721,981
Balance, Weighted Average Exercise Price (in dollars per share) | $ / shares	$ 2.03