Consolidated Statements Of Income And Earnings Reinvested In The Business (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
INCOME
Operating Revenues	$ 375,195	$ 523,909
Operating Expenses
Purchased Gas	42,068	127,091
Operation and Maintenance	112,692	112,582
Property, Franchise and Other Taxes	20,357	20,929
Depreciation, Depletion and Amortization	70,551	102,747
Impairment of Oil and Gas Producing Properties	435,451	0
Total Operating Expenses	681,119	363,349
Operating Income (Loss)	(305,924)	160,560
Other Income (Expense):
Interest Income	1,799	1,258
Other Income	2,418	1,183
Interest Expense on Long-Term Debt	(30,372)	(22,311)
Other Interest Expense	(1,380)	(790)
Income (Loss) Before Income Taxes	(333,459)	139,900
Income Tax Expense (Benefit)	(144,350)	55,160
Net Income (Loss) Available for Common Stock	(189,109)	84,740
EARNINGS REINVESTED IN THE BUSINESS
Balance at Beginning of Period	1,103,200	1,614,361
Beginning Retained Earnings Unappropriated And Current Period Net Income Loss	914,091	1,699,101
Dividends on Common Stock	(33,472)	(32,442)
Balance at December 31	$ 880,619	$ 1,666,659
Earnings Per Common Share, Basic:
Net Income (Loss) Available for Common Stock (in dollars per share)	$ (2.23)	$ 1.01
Earnings Per Common Share, Diluted:
Net Income (Loss) Available for Common Stock (in dollars per share)	$ (2.23)	$ 1.00
Weighted Average Common Shares Outstanding:
Used in Basic Calculation (shares)	84,651,233	84,208,645
Used in Diluted Calculation (shares)	84,651,233	85,118,516
Dividends Per Common Share:
Dividends Declared (in dollars per share)	$ 0.395	$ 0.385