Summary Of Significant Accounting Policies (Components Of Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Accumulated Other Comprehensive Loss [Roll Forward]
Balance at Beginning of Period	$ (47,760)	$ (34,091)	$ (30,123)	$ (5,640)
Other Comprehensive Gains and Losses Before Reclassifications	(27,199)	11,546	(39,862)	7,385
Amounts Reclassified From Other Comprehensive Income (Loss)	2,563	(10,759)	(2,411)	(35,049)
Balance at End of Period	(72,396)	(33,304)	(72,396)	(33,304)
Gains And Losses On Derivative Financial Instruments [Member]
Accumulated Other Comprehensive Loss [Roll Forward]
Balance at Beginning of Period	3,841	36,257	20,801	64,782
Other Comprehensive Gains and Losses Before Reclassifications	(27,036)	10,641	(39,294)	5,937
Amounts Reclassified From Other Comprehensive Income (Loss)	2,563	(10,759)	(2,139)	(34,580)
Balance at End of Period	(20,632)	36,139	(20,632)	36,139
Gains And Losses On Securities Available For Sale [Member]
Accumulated Other Comprehensive Loss [Roll Forward]
Balance at Beginning of Period	6,885	6,128	7,562	6,054
Other Comprehensive Gains and Losses Before Reclassifications	(163)	905	(568)	1,448
Amounts Reclassified From Other Comprehensive Income (Loss)	0	0	(272)	(469)
Balance at End of Period	6,722	7,033	6,722	7,033
Funded Status Of The Pension And Other Post-Retirement Benefit Plans [Member]
Accumulated Other Comprehensive Loss [Roll Forward]
Balance at Beginning of Period	(58,486)	(76,476)	(58,486)	(76,476)
Other Comprehensive Gains and Losses Before Reclassifications	0	0	0	0
Amounts Reclassified From Other Comprehensive Income (Loss)	0	0	0	0
Balance at End of Period	$ (58,486)	$ (76,476)	$ (58,486)	$ (76,476)