Note 17 - Stock-based Compensation - Performance Based Restricted Stock Units Assumptions (Details) - Performance-based Restriced Stock Units [Member] - $ / shares	12 Months Ended
	Jul. 31, 2023	Jul. 31, 2022	Jul. 31, 2021
Expected Risk Free Interest Rate	4.52%	2.80%	0.39%
Expected Volatility	84.56%	90.90%	78.03%
Expected Dividend Yield	0.00%	0.00%	0.00%
Expected Life in Years (Year)	3 years	3 years	3 years
Correlation	81.22%	76.89%	66.02%
Exercise Price (in dollars per share)	$ 3.32	$ 3.98	$ 2.15
Grant Date Fair Value (in dollars per share)	$ 3.35	$ 4.80	$ 2.48