Summary Of Significant Accounting Policies (Components Of Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Accumulated Other Comprehensive Loss [Roll Forward]
Balance at Beginning of Period	$ (54,286)	$ (47,760)	$ (67,750)	$ (30,123)
Other Comprehensive Gains and Losses Before Reclassifications	24,376	(27,199)	38,185	(39,862)
Amounts Reclassified From Other Comprehensive Income (Loss)	(2,756)	2,563	14,742	(2,411)
Reclassification Adjustment for the Cumulative Effect of Adoption of Authoritative Guidance for Financial Assets and Liabilities			(7,437)
Reclassification of Stranded Tax Effects Related to the 2017 Tax Reform Act	0	0	(10,406)	0
Balance at End of Period	(32,666)	(72,396)	(32,666)	(72,396)
Gains And Losses On Derivative Financial Instruments [Member]
Accumulated Other Comprehensive Loss [Roll Forward]
Balance at Beginning of Period	4,562	3,841	(28,611)	20,801
Other Comprehensive Gains and Losses Before Reclassifications	24,376	(27,036)	38,185	(39,294)
Amounts Reclassified From Other Comprehensive Income (Loss)	(2,756)	2,563	14,742	(2,139)
Reclassification Adjustment for the Cumulative Effect of Adoption of Authoritative Guidance for Financial Assets and Liabilities			0
Reclassification of Stranded Tax Effects Related to the 2017 Tax Reform Act			1,866
Balance at End of Period	26,182	(20,632)	26,182	(20,632)
Gains And Losses On Securities Available For Sale [Member]
Accumulated Other Comprehensive Loss [Roll Forward]
Balance at Beginning of Period	0	6,885	7,437	7,562
Other Comprehensive Gains and Losses Before Reclassifications	0	(163)	0	(568)
Amounts Reclassified From Other Comprehensive Income (Loss)	0	0	0	(272)
Reclassification Adjustment for the Cumulative Effect of Adoption of Authoritative Guidance for Financial Assets and Liabilities			(7,437)
Reclassification of Stranded Tax Effects Related to the 2017 Tax Reform Act			0
Balance at End of Period	0	6,722	0	6,722
Funded Status Of The Pension And Other Post-Retirement Benefit Plans [Member]
Accumulated Other Comprehensive Loss [Roll Forward]
Balance at Beginning of Period	(58,848)	(58,486)	(46,576)	(58,486)
Other Comprehensive Gains and Losses Before Reclassifications	0	0	0	0
Amounts Reclassified From Other Comprehensive Income (Loss)	0	0	0	0
Reclassification Adjustment for the Cumulative Effect of Adoption of Authoritative Guidance for Financial Assets and Liabilities			0
Reclassification of Stranded Tax Effects Related to the 2017 Tax Reform Act			(12,272)
Balance at End of Period	$ (58,848)	$ (58,486)	$ (58,848)	$ (58,486)

Accumulated Other Comprehensive Income [Roll Forward]

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- Definition

Reclassification Adjustment from AOCI for Cumulative Effect of Adoption of Authoritative Guidance for Financial Assets and Liabilities

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- Definition

Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

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Amount after tax, before reclassification adjustments of other comprehensive income (loss).

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Amount after tax of reclassification adjustments of other comprehensive income (loss).

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Amount of increase (decrease) in accumulated other comprehensive income (AOCI) for reclassification to retained earnings of tax effect from remeasurement of deferred tax pursuant to Tax Cuts and Jobs Act.

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