Consolidated Statements Of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
OPERATING ACTIVITIES
Net Income Available for Common Stock	$ 403,189	$ 407,879
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities:
Gain on Sale of Assets	0	12,736
Depreciation, Depletion and Amortization	299,973	275,681
Deferred Income Taxes	101,096	121,150
Stock-Based Compensation	15,807	15,178
Reduction of Other Post-Retirement Regulatory Liability	0	(18,533)
Other	16,640	27,527
Change in:
Receivables and Unbilled Revenue	192,324	(194,832)
Gas Stored Underground and Materials, Supplies and Emission Allowances	11,757	24,141
Unrecovered Purchased Gas Costs	75,244	716
Other Current Assets	(12,230)	(1,699)
Accounts Payable	(52,340)	19,259
Amounts Payable to Customers	21,972	271
Customer Advances	(26,108)	(17,223)
Customer Security Deposits	9,741	5,908
Other Accruals and Current Liabilities	45,363	61,322
Other Assets	(39,367)	(44,184)
Other Liabilities	(7,949)	(15,809)
Net Cash Provided by Operating Activities	1,055,112	654,016
INVESTING ACTIVITIES
Capital Expenditures	(727,738)	(592,487)
Net Proceeds from Sale of Oil and Gas Producing Properties	0	254,439
Acquisition of Upstream Assets	(124,758)	0
Sale of Fixed Income Mutual Fund Shares in Grantor Trust	10,000	30,000
Other	13,397	13,528
Net Cash Used in Investing Activities	(829,099)	(294,520)
FINANCING ACTIVITIES
Proceeds from Issuance of Short-Term Note Payable to Bank	250,000	0
Repayment of Short-Term Note Payable to Bank	(250,000)	0
Net Change in Other Short-Term Notes Payable to Banks and Commercial Paper	78,500	241,500
Net Proceeds from Issuance of Long-Term Debt	297,533	0
Reduction of Long-Term Debt	(549,000)	0
Dividends Paid on Common Stock	(130,653)	(124,701)
Net Repurchases of Common Stock	(6,696)	(9,387)
Net Cash Provided by (Used in) Financing Activities	(310,316)	107,412
Net Increase (Decrease) in Cash, Cash Equivalents, and Restricted Cash	(84,303)	466,908
Cash, Cash Equivalents and Restricted Cash at October 1	137,718	120,138
Cash, Cash Equivalents and Restricted Cash at June 30	53,415	587,046
Supplemental Disclosure of Cash Flow Information, Non-Cash Investing Activities:
Non-Cash Capital Expenditures	71,823	74,415
Non-Cash Contingent Consideration for Asset Sale	$ 0	$ 12,571