Summary Of Significant Accounting Policies (Components Of Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Accumulated Other Comprehensive Loss [Roll Forward]
Balance at Beginning of Period	$ (625,733)	$ (513,597)
Other Comprehensive Gains and Losses Before Reclassifications	216,216	118,483
Amounts Reclassified From Other Comprehensive Income	115,771	118,088
Balance at End of Period	(293,746)	(277,026)
Gains And Losses On Derivative Financial Instruments [Member]
Accumulated Other Comprehensive Loss [Roll Forward]
Balance at Beginning of Period	(572,163)	(449,962)
Other Comprehensive Gains and Losses Before Reclassifications	216,216	118,483
Amounts Reclassified From Other Comprehensive Income	115,771	118,088
Balance at End of Period	(240,176)	(213,391)
Funded Status Of The Pension And Other Post-Retirement Benefit Plans [Member]
Accumulated Other Comprehensive Loss [Roll Forward]
Balance at Beginning of Period	(53,570)	(63,635)
Other Comprehensive Gains and Losses Before Reclassifications	0	0
Amounts Reclassified From Other Comprehensive Income	0	0
Balance at End of Period	$ (53,570)	$ (63,635)