Summary Of Significant Accounting Policies (Schedule Of Other Accruals And Current Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013
Segment Reporting Information [Line Items]
Regulatory Liabilities	$ 17,597	$ 20,013
Reserve for Gas Replacement	(36,047)	(51,484)
Other	25,895	22,833
Total Other Accruals and Current Liabilities	102,709	83,946
Accrued Capital Expenditures [Member]
Segment Reporting Information [Line Items]
Other	35,749	41,100
Reserve For Gas Replacement [Member]
Segment Reporting Information [Line Items]
Reserve for Gas Replacement	7,003	0
Federal [Member]
Segment Reporting Information [Line Items]
Income Taxes Payable	14,563	0
State [Member]
Segment Reporting Information [Line Items]
Income Taxes Payable	$ 1,902	$ 0