Stock Based Compensation (Schedule Of Restricted Stock Units Activity) (Details) (USD $)	6 Months Ended	12 Months Ended
Mar. 31, 2013	Sep. 30, 2012
Stock-Based Compensation [Abstract]
Outstanding Beginning Balance, Number of Restricted Stock Units	99,725	69,378
Outstanding Beginning Balance, Weighted Average Grant Date Fair Value Per Share	$ 32.69	$ 36.10
Granted, Number of Restricted Stock Units	58,775	54,825
Granted, Weighted Average Grant Date Fair Value Per Share	$ 38.82	$ 31.18
Expired or cancelled, Number of Restricted Stock Units		(24,478)
Expired or cancelled, Weighted Average Grant Date Fair Value Per Share		$ 38.71
Vested/exercised, Number of Restricted Stock Units	(34,520)
Vested/exercised, Weighted Average Grant Date Fair Value Per Share	$ 31.18
Outstanding Ending balance, Number of Restricted Stock Units	123,980	99,725
Outstanding Ending balance, Weighted Average Grant Date Fair Value Per Share	$ 36.02	$ 32.69

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The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

+ References

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- Definition

Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

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The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

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