Consolidated Statements Of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
OPERATING ACTIVITIES
Net Income Available for Common Stock	$ 310,570	$ 299,720
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities:
Depreciation, Depletion and Amortization	197,564	179,823
Deferred Income Taxes	80,745	94,212
Stock-Based Compensation	11,286	10,631
Reduction of Other Post-Retirement Regulatory Liability	0	(18,533)
Other	10,758	14,494
Change in:
Receivables and Unbilled Revenue	71,760	(166,584)
Gas Stored Underground and Materials, Supplies and Emission Allowances	21,243	32,040
Unrecovered Purchased Gas Costs	72,491	29,377
Other Current Assets	(15,864)	(8,605)
Accounts Payable	(29,169)	2,006
Amounts Payable to Customers	2,411	3,401
Customer Advances	(26,108)	(17,223)
Customer Security Deposits	10,099	1,474
Other Accruals and Current Liabilities	28,741	11,164
Other Assets	(26,901)	(32,659)
Other Liabilities	(8,417)	(9,119)
Net Cash Provided by Operating Activities	711,209	425,619
INVESTING ACTIVITIES
Capital Expenditures	(496,362)	(415,415)
Net Proceeds from Sale of Oil and Gas Producing Properties	0	13,525
Deposit Paid for Upstream Assets	(12,700)	0
Sale of Fixed Income Mutual Fund Shares in Grantor Trust	10,000	30,000
Other	14,413	13,689
Net Cash Used in Investing Activities	(484,649)	(358,201)
FINANCING ACTIVITIES
Proceeds from Issuance of Short-Term Note Payable to Bank	250,000	0
Net Change in Other Short-Term Notes Payable to Banks and Commercial Paper	100,000	59,500
Reduction of Long-Term Debt	(549,000)	0
Dividends Paid on Common Stock	(87,051)	(83,091)
Net Repurchases of Common Stock	(6,694)	(9,026)
Net Cash Used in Financing Activities	(292,745)	(32,617)
Net Increase (Decrease) in Cash, Cash Equivalents, and Restricted Cash	(66,185)	34,801
Cash, Cash Equivalents and Restricted Cash at October 1	137,718	120,138
Cash, Cash Equivalents and Restricted Cash at March 31	71,533	154,939
Supplemental Disclosure of Cash Flow Information, Non-Cash Investing Activities:
Non-Cash Capital Expenditures	$ 64,495	$ 63,490