Summary Of Significant Accounting Policies (Components Of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Accumulated Other Comprehensive Income [Roll Forward]
Balance at Beginning of Period	$ 126,689	$ (45,055)	$ (3,979)	$ (19,234)
Other Comprehensive Gains and Losses Before Reclassification	(5,366)	(4,794)	170,690	(40,200)
Amounts Reclassified From Other Comprehensive Income (Loss)	(29,075)	6,211	(74,463)	15,796
Balance at End of Period	92,248	(43,638)	92,248	(43,638)
Gains And Losses On Derivative Financial Instruments [Member]
Accumulated Other Comprehensive Income [Roll Forward]
Balance at Beginning of Period	174,413	2,937	43,659	30,722
Other Comprehensive Gains and Losses Before Reclassification	(5,423)	(5,565)	170,719	(42,935)
Amounts Reclassified From Other Comprehensive Income (Loss)	(29,075)	6,202	(74,463)	15,787
Balance at End of Period	139,915	3,574	139,915	3,574
Gains And Losses On Securities Available For Sale [Member]
Accumulated Other Comprehensive Income [Roll Forward]
Balance at Beginning of Period	8,296	8,301	8,382	6,337
Other Comprehensive Gains and Losses Before Reclassification	57	771	(29)	2,735
Amounts Reclassified From Other Comprehensive Income (Loss)	0	9	0	9
Balance at End of Period	8,353	9,081	8,353	9,081
Funded Status Of The Pension And Other Post-Retirement Benefit Plans [Member]
Accumulated Other Comprehensive Income [Roll Forward]
Balance at Beginning of Period	(56,020)	(56,293)	(56,020)	(56,293)
Other Comprehensive Gains and Losses Before Reclassification	0	0	0	0
Amounts Reclassified From Other Comprehensive Income (Loss)	0	0	0	0
Balance at End of Period	$ (56,020)	$ (56,293)	$ (56,020)	$ (56,293)