Summary of Significant Accounting Policies (Schedule of Components of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Other Comprehensive Gains and Losses Before Reclassifications	$ 35,952	$ (39,113)
Amounts Reclassified From Other Comprehensive Income (Loss)	(9,720)	(21,564)
Gains and Losses on Derivative Financial Instruments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	19,950	55,799
Other Comprehensive Gains and Losses Before Reclassifications	35,952	(39,113)
Amounts Reclassified From Other Comprehensive Income (Loss)	(9,720)	(21,564)
Ending balance	46,182	(4,878)
Funded Status of the Pension and Other Post-Retirement Benefit Plans
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(79,172)	(71,275)
Other Comprehensive Gains and Losses Before Reclassifications	0	0
Amounts Reclassified From Other Comprehensive Income (Loss)	0	0
Ending balance	(79,172)	(71,275)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(59,222)	(15,476)
Ending balance	$ (32,990)	$ (76,153)