Note 11 - Long-term Debt (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2022	Jul. 31, 2021	Jul. 31, 2020
Repayments of Long-Term Debt, Total	$ 10,000	$ 10,000
Amortization of Debt Discount (Premium)	525	1,376	$ 1,670
Interest Paid, Including Capitalized Interest, Operating and Investing Activities, Total	409	1,255	$ 1,627
Credit Agreement [Member]
Repayments of Long-Term Debt, Total		10,000
Long-Term Debt, Gross	$ 0	$ 10,000
Third Amended and Restated Credit Agreement [Member]
Stock Issued During Period, Shares, Credit Facility (in shares)	161,594	1,249,039	1,743,462
Stock Issued During Period, Value, Credit Facility	$ 600	$ 1,170	$ 1,400