Summary of Significant Accounting Policies - Schedule of Other Accruals and Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Sep. 30, 2022
Accounting Policies [Abstract]
Accrued Capital Expenditures	$ 43,323	$ 64,720
Regulatory Liabilities	38,105	31,293
Liability for Royalty and Working Interests	17,679	86,206
Non-Qualified Benefit Plan Liability	13,052	17,474
Other	48,815	57,634
Other Accruals and Current Liabilities	$ 160,974	$ 257,327