Note 14 - Capital Stock - Number of Shares Issued and Cash Received upon Exercise of the Stock Options (Details) - USD ($)	3 Months Ended				9 Months Ended
	Apr. 30, 2021	Jan. 31, 2021	Oct. 31, 2020	Apr. 30, 2020	Apr. 30, 2021	Apr. 30, 2020
Number of Options Exercised on Forfeiture Basis (in shares)	988,909				1,930,691
Number of Options Exercised on Cash Basis (in shares)	953,939				1,141,439
Total Number of Options Exercised (in shares)	1,942,848	1,100,782	28,500		3,072,130
Number of Shares Issued on Cash Exercise (in shares)	953,939				1,141,439
Number of Shares Issued on Forfeiture Basis (in shares)	557,608				943,168
Total Number of Shares Issued Upon Exercise of Options (in shares)	1,511,547				2,084,607
Cash Received from Exercise of Stock Options	$ 1,086,844				$ 1,308,278
Total Intrinsic Value of Options Exercised	$ 3,026,602				$ 3,855,217