Note 15 - Stock-based Compensation - Summary of Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2022	Jul. 31, 2021	Jul. 31, 2020
Share-Based Payment Arrangement, Noncash Expense, Total	$ 4,681	$ 5,471	$ 3,493
Common stock issued	1,478	1,594	1,123
Settlement of share issuance obligation	0	0	(15)
Share-Based Payment Arrangement, Employee [Member]
Amortization of expenses	960	982	640
Share-Based Payment Arrangement, Noncash Expense, Total	2,185	2,182	1,275
Common stock issued	1,187	1,200	635
Amortization of RSU expenses	38	0	0
Consultants [Member]
Common stock issued to consultants	770	877	540
Amortization of expenses	220	288	240
Share-Based Payment Arrangement, Noncash Expense, Total	990	1,165	780
Management [Member]
Amortization of expenses	471	774	645
Share-Based Payment Arrangement, Noncash Expense, Total	1,506	2,124	1,453
Common stock issued	0	135	225
Management [Member] | Restricted Stock Units (RSUs) and Performance Restricted Stock Units (PRSUs) [Member]
Amortization of expenses	$ 1,035	$ 1,215	$ 583