Summary Of Significant Accounting Policies (Reclassification Out Of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Reclassification Adjustments out of Accumulated Other Comprehensive Income (Loss) [Line Items]
Operating Revenues	$ 417,442	$ 428,704	$ 1,572,742	$ 1,804,824
Total Before Income Tax	(82,469)	125,555	315,242	543,614
Income Tax Expense	28,311	(32,935)	(70,108)	(140,425)
Net Income Available for Common Stock	(54,158)	92,620	245,134	403,189
Amount of Gain or (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss)
Reclassification Adjustments out of Accumulated Other Comprehensive Income (Loss) [Line Items]
Total Before Income Tax	75,346	57,692	155,203	(120,590)
Income Tax Expense	(20,906)	(15,813)	(43,064)	32,967
Net Income Available for Common Stock	54,440	41,879	112,139	(87,623)
Amount of Gain or (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) | Commodity Contracts | Gains and Losses on Derivative Financial Instruments
Reclassification Adjustments out of Accumulated Other Comprehensive Income (Loss) [Line Items]
Operating Revenues	75,462	57,842	155,401	(120,088)
Amount of Gain or (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) | Foreign Currency Contracts | Gains and Losses on Derivative Financial Instruments
Reclassification Adjustments out of Accumulated Other Comprehensive Income (Loss) [Line Items]
Operating Revenues	$ (116)	$ (150)	$ (198)	$ (502)