Summary Of Significant Accounting Policies (Schedule Of Other Accruals And Current Liabilities) (Details) - USD ($) $ in Thousands	Mar. 31, 2025	Sep. 30, 2024
Summary Of Significant Accounting Policies [Line Items]
Accrued Capital Expenditures	$ 40,449	$ 47,344
Regulatory Liabilities	16,285	29,352
Reserve for Gas Replacement	27,614	0
Liability for Royalty and Working Interests	30,697	15,007
Non-Qualified Benefit Plan Liability	14,135	14,135
Other	47,049	57,065
Other Accruals and Current Liabilities	184,925	162,903
Federal
Summary Of Significant Accounting Policies [Line Items]
Federal Income Taxes Payable	$ 8,696	$ 0