Consolidated Statements Of Cash Flows (USD $) In Thousands	9 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
OPERATING ACTIVITIES
Net Income Available for Common Stock	$ 221,045	$ 187,512
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities:
Gain on Sale of Unconsolidated Subsidiaries	(50,879)
Depreciation, Depletion and Amortization	170,617	142,433
Deferred Income Taxes	140,326	63,813
(Income) Loss from Unconsolidated Subsidiaries, Net of Cash Distributions	4,976	904
Excess Tax Costs (Benefits) Associated with Stock-Based Compensation Awards	1,224	(13,207)
Other	2,375	7,884
Change in:
Hedging Collateral Deposits	(26,850)	(7,374)
Receivables and Unbilled Utility Revenue	(25,919)	6,676
Gas Stored Underground and Materials and Supplies	22,387	20,384
Prepayments and Other Current Assets	69,960	39,043
Accounts Payable	5,506	127
Amounts Payable to Customers	(12,448)	(54,764)
Customer Advances	(26,617)	(23,526)
Customer Security Deposits	(648)	1,188
Other Accruals and Current Liabilities	36,743	30,961
Other Assets	20,255	29,197
Other Liabilities	(15,771)	(11,358)
Net Cash Provided by Operating Activities	536,282	419,893
INVESTING ACTIVITIES
Capital Expenditures	(583,739)	(327,513)
Net Proceeds from Sale of Unconsolidated Subsidiaries	59,365
Net Proceeds from Sale of Oil and Gas Producing Properties	69,435
Other	(2,908)	(273)
Net Cash Used in Investing Activities	(457,847)	(327,786)
FINANCING ACTIVITIES
Excess Tax (Costs) Benefits Associated with Stock-Based Compensation Awards	(1,224)	13,207
Reduction of Long-Term Debt	(200,000)
Dividends Paid on Common Stock	(85,201)	(81,318)
Net Proceeds from Issuance (Repurchase) of Common Stock	(4,471)	26,798
Net Cash Used in Financing Activities	(290,896)	(41,313)
Net Increase (Decrease) in Cash and Temporary Cash Investments	(212,461)	50,794
Cash and Temporary Cash Investments at October 1	397,171	408,053
Cash and Temporary Cash Investments at June 30	$ 184,710	$ 458,847