Note 13 - Capital Stock - Number of Shares Issued and Cash Received upon Exercise of the Stock Options (Details) - USD ($)	12 Months Ended
	Jul. 31, 2020	Jul. 31, 2019	Jul. 31, 2018
Number of Shares Issued Upon Exercise of Options (in shares)		125,879	1,094,589
Number of Options Exercised on Forfeiture Basis (in shares)		193,375	580,625
Number of Net Shares Issued (in shares)		59,629	309,589
Number of Options Exercised on Cash Basis (in shares)		66,250	785,000
Cash Received from Exercise of Stock Options		$ 72,363	$ 530,050
Total Intrinsic Value of Options Exercised		$ 134,174	$ 1,049,694