Summary Of Significant Accounting Policies (Components Of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	$ (15,476)	$ (55,060)
Other Comprehensive Gains and Losses Before Reclassifications	(39,113)	136,681
Amounts Reclassified From Other Comprehensive Income (Loss)	(21,564)	(14,240)
Ending balance	(76,153)	67,381
Gains and Losses on Derivative Financial Instruments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	55,799	4,623
Other Comprehensive Gains and Losses Before Reclassifications	(39,113)	136,681
Amounts Reclassified From Other Comprehensive Income (Loss)	(21,564)	(14,240)
Ending balance	(4,878)	127,064
Funded Status of the Pension and Other Post-Retirement Benefit Plans
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(71,275)	(59,683)
Other Comprehensive Gains and Losses Before Reclassifications	0	0
Amounts Reclassified From Other Comprehensive Income (Loss)	0	0
Ending balance	$ (71,275)	$ (59,683)