Note 13 - Capital Stock - Number of Shares Issued and Cash Received Upon Exercise of the Stock Options (Details) - USD ($) $ in Thousands	3 Months Ended				9 Months Ended
	Apr. 30, 2023	Jan. 31, 2023	Oct. 31, 2022	Apr. 30, 2022	Apr. 30, 2023	Apr. 30, 2022
Number of Options Exercised on Cash Basis (in shares)	0			404,832	138,537	807,580
Number of Options Exercised on Forfeiture Basis (in shares)	337,500			777,773	2,727,295	1,650,402
Total Number of Options Exercised (in shares)	337,500	197,110	2,331,222	1,182,605	2,865,832	2,457,982
Number of Shares Issued on Cash Exercise (in shares)	0			404,832	138,537	807,580
Number of Shares Issued on Forfeiture Basis (in shares)	204,693			595,478	1,565,059	1,140,065
Total Number of Shares Issued Upon Exercise of Options (in shares)	204,693			1,000,310	1,703,596	1,947,645
Cash Received from Exercise of Stock Options	$ 0			$ 404	$ 206	$ 851
Total Intrinsic Value of Options Exercised	$ 858			$ 4,891	$ 6,834	$ 7,685