Note 4 - Anfield Debt Settlement and Property Swap (Details Textual) $ / shares in Units, $ in Thousands				12 Months Ended
		Jun. 07, 2022 USD ($) $ / shares shares	Apr. 19, 2022 USD ($) shares	Jul. 31, 2022 USD ($) $ / shares	Jul. 31, 2021 USD ($) $ / shares	Jul. 31, 2020 USD ($) $ / shares	Apr. 19, 2022 $ / shares shares	Dec. 17, 2021 USD ($)	Sep. 23, 2020 $ / shares	Jul. 31, 2019 $ / shares
Class of Warrant or Right, Exercise Price of Warrants or Rights (in CAD per share) | $ / shares				$ 1.92	$ 1.90	$ 2.03				$ 1.94
Share Price (in dollars per share) | $ / shares									$ 0.96
Financing Receivable, Allowance for Credit Loss, Recovery				$ 18,342	$ 0	$ 0
Gain (Loss) on Settlement Debt Receivable				1,780	0	0
Gain (Loss) on Disposition of Assets, Total				6,427	$ (2)	$ 2
Swap Agreement [Member]
Swap Agreement, Fair Value Received		$ 6,500
Swap Agreement, Carrying Value Exchanged		92
Swap Agreement, Surrender Value		6,500
Gain (Loss) on Disposition of Assets, Total		$ 6,408
Settlement Agreement [Member] | Anfield Energy, Inc. [Member]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners		16.00%
Anfield Warrant [Member]
Warrants, Carrying Value Per Share (in dollars per share) | $ / shares		$ 0.03
Anfield Energy, Inc. [Member]
Proceeds from Sale and Collection of Receivables, Total			$ 9,171
Debt Units Amount Received in Settlement of Indebtedness			$ 9,171
Share Price (in dollars per share) | $ / shares		$ 0.08
Anfield Energy, Inc. [Member] | Settlement Agreement [Member]
Proceeds from Sale and Collection of Receivables, Total		$ 9,171
Common Shares Received in Settlement of Indebtedness (in shares) | shares		96,272,918
Common Shares Received in Settlement of Indebtedness, Fair Value		$ 7,702
Financing Receivable, Allowance for Credit Loss, Recovery				18,342
Cash Payments and Warrants, Fair Value				20,122
Gain (Loss) on Settlement Debt Receivable				1,780
Anfield Energy, Inc. [Member] | Anfield Warrant [Member]
Common Share Purchase Warrant, Per Debt Unit Contains (in shares) | shares			1
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares) | shares							1
Class of Warrant or Right, Exercise Price of Warrants or Rights (in CAD per share) | $ / shares							$ 0.18
Anfield Energy, Inc. [Member] | Anfield Warrant [Member] | Settlement Agreement [Member]
Warrants Received in Settlement of Indebtedness (in shares) | shares		96,272,918
Warrants Received in Settlement of Indebtedness, Fair Value		$ 3,249
Anfield Energy, Inc. [Member] | Anfield Common Shares [Member]
Common Share, Per Debt Unit Contains (in shares) | shares			1
U1A Acquisition [Member]
Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed, Debt Receivable	[1]			0
U1A Acquisition [Member] | Anfield Energy, Inc. [Member]
Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed, Debt Receivable				$ 0				$ 18,342

[1] Other non-current assets included certain material and supply inventories classified as non-current and ROU assets associated with U1A’s operating leases. The fair value of long-term inventory was determined to approximate its carrying value. ROU assets and lease liabilities for operating leases are measured based on the present value of the future lease payments over the remaining lease terms at the acquisition date.