Note 19 - Income Taxes - Deferred Tax Assets (Liabilities) (Details) - USD ($) $ in Thousands	Jul. 31, 2022	Jul. 31, 2021
Mineral properties	$ 1,401	$ 1,277
Exploration costs	1,875	6,547
Stock option expense	4,651	4,623
Depreciable property	1,078	(1,163)
Inventories	(3,955)	(3,608)
Asset retirement obligations	2,924	107
Other	654	81
Section 163(j) interest expense carry forwards	2,040	1,061
Loss carry forwards	70,162	49,988
Deferred Tax Assets, Gross, Total	80,830	58,913
Valuation allowance	(80,454)	(58,913)
Deferred tax assets	0	0
Deferred tax assets, other comprehensive loss	0	0
Mineral properties	(536)	(541)
Net deferred tax liabilities	$ (536)	$ (541)