Note 10 - Supplemental Financial Data - Oil and Gas Producing Activities (Unaudited): Schedule of Proved Developed and Undeveloped Oil and Gas Reserve Quantities (Details)	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2020
Details
Net Proved Developed And Undeveloped Reserves	1,600	1,300	1,000
Proved Developed And Undeveloped Reserves, Revisions of previous estimates	700	600
Proved Developed And Undeveloped Reserve, Production	(400)	(300)