Note 7 - Related-party Debt (Details Textual) - USD ($) $ in Thousands			12 Months Ended
	Sep. 05, 2022	Sep. 03, 2021	Jun. 30, 2024	Jun. 30, 2023	Sep. 30, 2022	Feb. 13, 2020	Sep. 05, 2019
Interest Paid, Excluding Capitalized Interest, Operating Activities			$ 26	$ 69
Secured Promissory Note (2019 Note) [Member]
Repayments of Debt	$ 500	$ 1,000
Interest Paid, Excluding Capitalized Interest, Operating Activities	$ 55	330
Notes Payable, Total					$ 500
Secured Promissory Note (2019 Note) [Member] | Chief Executive Officer and Board of Directors Chairman, Thomas B. Pickens III [Member]
Debt Instrument, Face Amount							$ 1,500
Secured Promissory Note, (2020 Note) [Member]
Repayments of Debt		1,000
Interest Paid, Excluding Capitalized Interest, Operating Activities		$ 172
Secured Promissory Note, (2020 Note) [Member] | Chief Executive Officer and Board of Directors Chairman, Thomas B. Pickens III [Member]
Debt Instrument, Face Amount						$ 1,000
Secured Promissory Notes, "Original Notes" [Member] | Chief Executive Officer and Board of Directors Chairman, Thomas B. Pickens III [Member]
Debt Instrument, Interest Rate, Stated Percentage						11.00%