Consolidated Statements Of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
OPERATING ACTIVITIES
Net Income Available for Common Stock	$ 257,009	$ 353,527
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities:
Depreciation, Depletion and Amortization	200,990	177,802
Deferred Income Taxes	111,123	(43,537)
Stock-Based Compensation	16,144	11,770
Other	7,964	12,311
Change in:
Receivables and Unbilled Revenue	(31,584)	(35,021)
Gas Stored Underground and Materials and Supplies	17,551	18,832
Unrecovered Purchased Gas Costs	4,204	4,623
Other Current Assets	11,972	(1,185)
Accounts Payable	(16,132)	2,327
Amounts Payable to Customers	11,152	16,833
Customer Advances	(13,443)	(15,504)
Customer Security Deposits	(8,902)	(1,904)
Other Accruals and Current Liabilities	36,040	26,538
Other Assets	(34,594)	(10,770)
Other Liabilities	1,061	1,441
Net Cash Provided by Operating Activities	570,555	518,083
INVESTING ACTIVITIES
Capital Expenditures	(587,442)	(403,994)
Net Proceeds from Sale of Oil and Gas Producing Properties	0	55,506
Other	(3,071)	(1,759)
Net Cash Used in Investing Activities	(590,513)	(350,247)
Financing Activities
Reduction of Long-Term Debt	0	(307,047)
Dividends Paid on Common Stock	(109,875)	(106,732)
Net Repurchases of Common Stock	(8,864)
Net Proceeds from Issuance of Common Stock		4,262
Net Cash Used in Financing Activities	(118,739)	(409,517)
Net Decrease in Cash, Cash Equivalents, and Restricted Cash	(138,697)	(241,681)
Cash, Cash Equivalents and Restricted Cash at October 1	233,047	557,271
Cash, Cash Equivalents and Restricted Cash at June 30	94,350	315,590
Supplemental Disclosure of Cash Flow Information, Non-Cash Investing Activities:
Non-Cash Capital Expenditures	$ 79,425	$ 71,410