Consolidated Statements Of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
OPERATING ACTIVITIES
Net Income (Loss) Available for Common Stock	$ 190,210	$ (19,477)
Adjustments to Reconcile Net Income (Loss) to Net Cash Provided by Operating Activities:
Gain on Sale of Timber Properties	(51,066)	0
Impairment of Oil and Gas Producing Properties	76,152	177,761
Depreciation, Depletion and Amortization	167,462	152,830
Deferred Income Taxes	61,408	104,883
Premium Paid on Early Redemption of Debt	15,715	0
Stock-Based Compensation	8,657	7,580
Other	6,742	9,800
Change in:
Receivables and Unbilled Revenue	(101,159)	(58,248)
Gas Stored Underground and Materials, Supplies and Emission Allowances	27,258	20,086
Unrecovered Purchased Gas Costs	(479)	2,246
Other Current Assets	(8,447)	(3,134)
Accounts Payable	8,613	(5,465)
Amounts Payable to Customers	8,980	13,196
Customer Advances	(15,319)	(12,429)
Customer Security Deposits	2,304	(1,211)
Other Accruals and Current Liabilities	9,058	9,076
Other Assets	11,039	(10,359)
Other Liabilities	5	3,857
Net Cash Provided by Operating Activities	417,133	390,992
INVESTING ACTIVITIES
Capital Expenditures	(338,867)	(395,486)
Net Proceeds from Sale of Timber Properties	104,582	0
Other	12,095	4,167
Net Cash Used in Investing Activities	(222,190)	(391,319)
Financing Activities
Changes in Notes Payable to Banks and Commercial Paper	(30,000)	174,800
Net Proceeds from Issuance of Long-Term Debt	495,267	0
Reduction of Long-term Debt	(515,715)	0
Dividends Paid on Common Stock	(81,035)	(75,197)
Net Repurchases of Common Stock	(3,534)	(4,153)
Net Cash Provided by (Used in) Financing Activities	(135,017)	95,450
Net Increase in Cash, Cash Equivalents, and Restricted Cash	59,926	95,123
Cash, Cash Equivalents and Restricted Cash at October 1	20,541	27,260
Cash, Cash Equivalents and Restricted Cash at March 31	80,467	122,383
Supplemental Disclosure of Cash Flow Information, Non-Cash Investing Activities:
Non-Cash Capital Expenditures	$ 68,073	$ 59,490