Note 13 - Capital Stock - Schedule of Outstanding Stock Options (Details) - $ / shares	3 Months Ended			6 Months Ended
	Jan. 31, 2021	Oct. 31, 2020	Jan. 31, 2020	Jan. 31, 2021	Jan. 31, 2020
Balance, number of stock options (in shares)	14,171,250	15,514,750		15,514,750
Balance, Weighted Average Exercise Price (in dollars per share)	$ 1.10	$ 1.13		$ 1.13
Exercised, number of stock options (in shares)	(1,100,782)	(28,500)		(1,129,282)
Exercised Options, Weighted Average Exercise Price (in dollars per share)	$ 1.11	$ 0.93
Expired, number of stock options (in shares)		(1,315,000)
Expired, Weighted Average Exercise Price (in dollars per share)		$ 1.43
Balance, number of stock options (in shares)	13,070,468	14,171,250		13,070,468
Balance, Weighted Average Exercise Price (in dollars per share)	$ 1.10	$ 1.10		$ 1.10