Consolidated Statements Of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
OPERATING ACTIVITIES
Net Income Available for Common Stock	$ 407,879	$ 276,685
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities:
Gain on Sale of Assets	(12,736)	(51,066)
Impairment of Oil and Gas Producing Properties	0	76,152
Depreciation, Depletion and Amortization	275,681	251,632
Deferred Income Taxes	121,150	89,277
Premium Paid on Early Redemption of Debt	0	15,715
Stock-Based Compensation	15,178	12,296
Reduction of Other Post-Retirement Regulatory Liability	(18,533)	0
Other	27,527	7,795
Change in:
Receivables and Unbilled Revenue	(194,832)	(40,733)
Gas Stored Underground and Materials, Supplies and Emission Allowances	24,141	19,024
Unrecovered Purchased Gas Costs	716	0
Other Current Assets	(1,699)	(4,282)
Accounts Payable	19,259	7,474
Amounts Payable to Customers	271	(3,595)
Customer Advances	(17,223)	(15,319)
Customer Security Deposits	5,908	2,073
Other Accruals and Current Liabilities	61,322	23,154
Other Assets	(44,184)	5,839
Other Liabilities	(15,809)	(311)
Net Cash Provided by Operating Activities	654,016	671,810
INVESTING ACTIVITIES
Capital Expenditures	(592,487)	(512,775)
Net Proceeds from Sale of Oil and Gas Producing Properties	254,439	0
Net Proceeds from Sale of Timber Properties	0	104,582
Sale of Fixed Income Mutual Fund Shares in Grantor Trust	30,000	0
Other	13,528	11,223
Net Cash Used in Investing Activities	(294,520)	(396,970)
FINANCING ACTIVITIES
Changes in Notes Payable to Banks and Commercial Paper	241,500	(30,000)
Net Proceeds from Issuance of Long-Term Debt	0	495,267
Reduction of Long-Term Debt	0	(515,715)
Dividends Paid on Common Stock	(124,701)	(121,606)
Net Repurchases of Common Stock	(9,387)	(3,605)
Net Cash Provided by (Used in) Financing Activities	107,412	(175,659)
Net Increase in Cash, Cash Equivalents, and Restricted Cash	466,908	99,181
Cash, Cash Equivalents and Restricted Cash at October 1	120,138	20,541
Cash, Cash Equivalents and Restricted Cash at June 30	587,046	119,722
Supplemental Disclosure of Cash Flow Information, Non-Cash Investing Activities:
Non-Cash Capital Expenditures	74,415	81,485
Non-Cash Contingent Consideration for Asset Sale	$ 12,571	$ 0