Note 15 - Stock-based Compensation - Forfeited as Payment of Tax Withhold (Details) - Restricted Stock Units (RSUs) [Member] - shares	12 Months Ended
	Jul. 31, 2022	Jul. 31, 2021	Jul. 31, 2020
Number of RSUs vested (in shares)	508,368	1,025,005	155,000
Number of net RSU shares issued (in shares)	267,681	536,361	105,844
Number of RSU shares forfeited as payments of withholding amount (in shares)	240,687	488,644	49,156