Summary Of Significant Accounting Policies (Components Of Accumulated Other Comprehensive Income (Loss)) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Accumulated Other Comprehensive Income [Roll Forward]
Balance at Beginning of Period	$ (3,979)	$ (19,234)
Other Comprehensive Gains and Losses Before Reclassification	140,628	3,080
Amounts Reclassified From Other Comprehensive Income (Loss)	(14,176)	(5,884)
Balance at End of Period	122,473	(22,038)
Gains And Losses On Derivative Financial Instruments [Member]
Accumulated Other Comprehensive Income [Roll Forward]
Balance at Beginning of Period	43,659	30,722
Other Comprehensive Gains and Losses Before Reclassification	140,880	1,507
Amounts Reclassified From Other Comprehensive Income (Loss)	(14,176)	(5,884)
Balance at End of Period	170,363	26,345
Gains And Losses On Securities Available For Sale [Member]
Accumulated Other Comprehensive Income [Roll Forward]
Balance at Beginning of Period	8,382	6,337
Other Comprehensive Gains and Losses Before Reclassification	(252)	1,573
Amounts Reclassified From Other Comprehensive Income (Loss)	0	0
Balance at End of Period	8,130	7,910
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)
Other Comprehensive Gains and Losses Before Reclassification	0	0
Amounts Reclassified From Other Comprehensive Income (Loss)	0	0
Balance at End of Period	$ (56,020)	$ (56,293)