Summary Of Significant Accounting Policies (Schedule Of Other Accruals And Current Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Sep. 30, 2013
Segment Reporting Information [Line Items]
Regulatory Liabilities	$ 14,109	$ 20,013
Reserve for Gas Replacement	(20,183)	(51,484)
Other	20,883	22,833
Other Accruals and Current Liabilities	154,145	83,946
Accrued Capital Expenditures [Member]
Segment Reporting Information [Line Items]
Other	82,021	41,100
Reserve For Gas Replacement [Member]
Segment Reporting Information [Line Items]
Reserve for Gas Replacement	30,526	0
Federal [Member]
Segment Reporting Information [Line Items]
Income Taxes Payable	709	0
State [Member]
Segment Reporting Information [Line Items]
Income Taxes Payable	$ 5,897	$ 0