Consolidated Statements Of Income And Earnings Reinvested In The Business (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
INCOME
Operating Revenues	$ 502,624	$ 394,397	$ 1,750,900	$ 1,386,671
Operating Expenses:
Purchased Gas	67,948	18,737	369,168	177,018
Property, Franchise and Other Taxes	25,874	24,492	78,093	71,259
Depreciation, Depletion and Amortization	95,857	84,170	275,681	251,632
Impairment of Oil and Gas Producing Properties	0	0	0	76,152
Total Operating Expenses	334,663	244,327	1,126,915	930,086
Gain on Sale of Assets	12,736	0	12,736	51,066
Operating Income	180,697	150,070	636,721	507,651
Other Income (Expense):
Other Income (Deductions)	(5,649)	(2,028)	3,291	(15,078)
Interest Expense on Long-Term Debt	(30,091)	(30,220)	(90,300)	(111,296)
Other Interest Expense	(3,882)	(1,012)	(6,561)	(4,630)
Income Before Income Taxes	141,075	116,810	543,151	376,647
Income Tax Expense	32,917	30,335	135,272	99,962
Net Income Available for Common Stock	108,158	86,475	407,879	276,685
EARNINGS REINVESTED IN THE BUSINESS
Balance at Beginning of Period	1,407,683	1,100,718	1,191,175	991,630
Beginning Retained Earnings Unappropriated And Current Period Net Income	1,515,841	1,187,193	1,599,054	1,268,315
Dividends on Common Stock	(43,446)	(41,493)	(126,659)	(122,615)
Balance at June 30	$ 1,472,395	$ 1,145,700	$ 1,472,395	$ 1,145,700
Earnings Per Common Share, Basic:
Net Income Available for Common Stock (in dollars per share)	$ 1.18	$ 0.95	$ 4.46	$ 3.04
Earnings Per Common Share, Diluted:
Net Income Available for Common Stock (in dollars per share)	$ 1.17	$ 0.94	$ 4.43	$ 3.02
Weighted Average Common Shares Outstanding:
Used in Basic Calculation (shares)	91,456,265	91,172,683	91,388,417	91,113,973
Used in Diluted Calculation (shares)	92,168,518	91,762,898	92,083,560	91,642,849
Dividends Per Common Share:
Dividends Declared (in dollars per share)	$ 0.475	$ 0.455	$ 1.385	$ 1.345
Utility and Energy Marketing [Member]
INCOME
Operating Revenues	$ 179,888	$ 126,933	$ 785,664	$ 587,247
Operating Expenses:
Operation and Maintenance	46,403	42,577	146,523	139,521
Exploration and Production and Other [Member]
INCOME
Operating Revenues	252,638	209,618	758,594	621,933
Operating Expenses:
Operation and Maintenance	64,593	43,112	160,016	127,033
Pipeline and Storage and Gathering [Member]
INCOME
Operating Revenues	70,098	57,846	206,642	177,491
Operating Expenses:
Operation and Maintenance	$ 33,988	$ 31,239	$ 97,434	$ 87,471