Note 14 - Stock-based Compensation - Number of Shares Issued and Cash Received upon Exercise of the Stock Options (Details) - USD ($)	12 Months Ended
	Jul. 31, 2021	Jul. 31, 2020
Number of Options Exercised on Forfeiture Basis (in shares)	2,970,878
Number of Options Exercised on Cash Basis (in shares)	1,734,127
Total Number of Options Exercised (in shares)	4,705,005
Number of Shares Issued on Cash Exercise (in shares)	1,734,127
Number of Shares Issued on Forfeiture Basis (in shares)	1,592,128
Total Number of Shares Issued Upon Exercise of Options (in shares)	3,326,255
Cash Received from Exercise of Stock Options	$ 1,915,995
Total Intrinsic Value of Options Exercised	$ 6,882,464