Supplementary Information for Exploration and Production Activities - Summary of Capitalized Costs of Unproved Properties Excluded from Amortization (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Capitalized Costs of Unproved Properties Excluded from Amortization [Line Items]
Acquisition Costs	$ 8,136	$ 104,858	$ 2,072
Development Costs	46,597	1,821	185
Exploration Costs	10,813	0	0
Capitalized Interest	778	0	0
Capitalized costs of unproved properties excluded from amortization, total	66,324	$ 106,679	$ 2,257
Capitalized Costs of Unproved Properties Cumulative Balance
Capitalized Costs of Unproved Properties Excluded from Amortization [Line Items]
Acquisition Costs	140,753
Development Costs	48,642
Exploration Costs	10,813
Capitalized Interest	778
Capitalized costs of unproved properties excluded from amortization, total	$ 200,986
Costs Incurred Prior to Fiscal 2022
Capitalized Costs of Unproved Properties Excluded from Amortization [Line Items]
Acquisition Costs				$ 25,687
Development Costs				39
Exploration Costs				0
Capitalized Interest				0
Capitalized costs of unproved properties excluded from amortization, total				$ 25,726