Summary Of Significant Accounting Policies (Schedule Of Other Accruals And Current Liabilities) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Sep. 30, 2014
Summary Of Significant Accounting Policies [Line Items]
Regulatory Liability	$ 62,124	$ 51,817
Other Accruals and Current Liabilities	96,557	136,672
Accrued Capital Expenditures [Member]
Summary Of Significant Accounting Policies [Line Items]
Other	53,652	80,348
Regulatory Liabilities [Member]
Summary Of Significant Accounting Policies [Line Items]
Regulatory Liability	5,346	18,072
Other Accruals [Member]
Summary Of Significant Accounting Policies [Line Items]
Other	30,703	32,454
Federal [Member]
Summary Of Significant Accounting Policies [Line Items]
Income Taxes Payable	5,686	0
State [Member]
Summary Of Significant Accounting Policies [Line Items]
Income Taxes Payable	$ 1,170	$ 5,798