Note 15 - Stock-based Compensation - Summary of Stock Options Assumptions (Details) - $ / shares	12 Months Ended
	Jul. 31, 2022	Jul. 31, 2021	Jul. 31, 2020
Granted, Weighted Average Grant-Date Fair Value (in dollars per share)	$ 2.45	$ 1.30	$ 0.45
Share-Based Payment Arrangement, Option [Member]
Expected Risk Free Interest Rate	2.73%	0.70%	0.40%
Expected Volatility	78.75%	72.57%	60.48%
Expected Life in Years (Year)	4 years 11 months 15 days	5 years	4 years 11 months 4 days
Expected Dividend Yield	0.00%	0.00%	0.00%
Granted, Weighted Average Grant-Date Fair Value (in dollars per share)	$ 2.45	$ 1.30	$ 0.45