SUPPLEMENTARY OIL AND NATURAL GAS INFORMATION (UNAUDITED) - PROVED RESERVES (Details) bbl in Thousands, Mcf in Thousands, Boe in Thousands	12 Months Ended
	Sep. 30, 2024 Boe bbl Mcf	Sep. 30, 2023 Boe bbl Mcf
Changes in the estimates of net interests in total proved reserves of oil, natural gas liquids and natural gas
Balance at the beginning of the period | Boe	2,343	1,939
Revisions of previous estimates | Boe	457	115
Extensions, discoveries and other additions | Boe	184	756
Acquisitions of reserves | Boe	9
Less sales of reserves | Boe	(79)
Less production | Boe	(491)	(467)
Balance at the end of the period | Boe	2,423	2,343
Canada
Changes in the estimates of net interests in total proved reserves of oil, natural gas liquids and natural gas
Balance at the beginning of the period | Boe	1,772	1,769
Revisions of previous estimates | Boe	430	5
Extensions, discoveries and other additions | Boe	184	379
Acquisitions of reserves | Boe	9
Less sales of reserves | Boe	(79)
Less production | Boe	(401)	(381)
Balance at the end of the period | Boe	1,915	1,772
United States
Changes in the estimates of net interests in total proved reserves of oil, natural gas liquids and natural gas
Balance at the beginning of the period | Boe	571	170
Revisions of previous estimates | Boe	27	110
Extensions, discoveries and other additions | Boe	0	377
Acquisitions of reserves | Boe	0
Less sales of reserves | Boe	0
Less production | Boe	(90)	(86)
Balance at the end of the period | Boe	508	571
Oil
Changes in the estimates of net interests in total proved reserves of oil, natural gas liquids and natural gas
Balance at the beginning of the period	899	875
Revisions of previous estimates	219	(24)
Extensions, discoveries and other additions	117	252
Acquisitions of reserves	4
Less sales of reserves	(54)
Less production	(203)	(204)
Balance at the end of the period	982	899
Oil | Canada
Changes in the estimates of net interests in total proved reserves of oil, natural gas liquids and natural gas
Balance at the beginning of the period	787	846
Revisions of previous estimates	222	(43)
Extensions, discoveries and other additions	117	167
Acquisitions of reserves	4
Less sales of reserves	(54)
Less production	(184)	(183)
Balance at the end of the period	892	787
Oil | United States
Changes in the estimates of net interests in total proved reserves of oil, natural gas liquids and natural gas
Balance at the beginning of the period	112	29
Revisions of previous estimates	(3)	19
Extensions, discoveries and other additions	0	85
Acquisitions of reserves	0
Less sales of reserves	0
Less production	(19)	(21)
Balance at the end of the period	90	112
Natural gas liquids
Changes in the estimates of net interests in total proved reserves of oil, natural gas liquids and natural gas
Balance at the beginning of the period	327	205
Revisions of previous estimates	85	30
Extensions, discoveries and other additions	15	144
Acquisitions of reserves	2
Less sales of reserves	(2)
Less production	(64)	(52)
Balance at the end of the period	363	327
Natural gas liquids | Canada
Changes in the estimates of net interests in total proved reserves of oil, natural gas liquids and natural gas
Balance at the beginning of the period	150	144
Revisions of previous estimates	70	1
Extensions, discoveries and other additions	15	32
Acquisitions of reserves	2
Less sales of reserves	(2)
Less production	(36)	(27)
Balance at the end of the period	199	150
Natural gas liquids | United States
Changes in the estimates of net interests in total proved reserves of oil, natural gas liquids and natural gas
Balance at the beginning of the period	177	61
Revisions of previous estimates	15	29
Extensions, discoveries and other additions	0	112
Acquisitions of reserves	0
Less sales of reserves	0
Less production	(28)	(25)
Balance at the end of the period	164	177
Natural gas
Changes in the estimates of net interests in total proved reserves of oil, natural gas liquids and natural gas
Balance at the beginning of the period | Mcf	6,701	4,985
Revisions of previous estimates | Mcf	908	822
Extensions, discoveries and other additions | Mcf	313	2,157
Acquisitions of reserves | Mcf	16
Less sales of reserves | Mcf	(139)
Less production | Mcf	(1,344)	(1,263)
Balance at the end of the period | Mcf	6,455	6,701
Natural gas | Canada
Changes in the estimates of net interests in total proved reserves of oil, natural gas liquids and natural gas
Balance at the beginning of the period | Mcf	5,010	4,519
Revisions of previous estimates | Mcf	826	435
Extensions, discoveries and other additions | Mcf	313	1,079
Acquisitions of reserves | Mcf	16
Less sales of reserves | Mcf	(139)
Less production | Mcf	(1,085)	(1,023)
Balance at the end of the period | Mcf	4,941	5,010
Natural gas | United States
Changes in the estimates of net interests in total proved reserves of oil, natural gas liquids and natural gas
Balance at the beginning of the period | Mcf	1,691	466
Revisions of previous estimates | Mcf	82	387
Extensions, discoveries and other additions | Mcf	0	1,078
Acquisitions of reserves | Mcf	0
Less sales of reserves | Mcf	0
Less production | Mcf	(259)	(240)
Balance at the end of the period | Mcf	1,514	1,691