Income Tax Expense (Schedule Of Actual Income Tax Expense (Benefit) From Continuing Operations) (Details)	12 Months Ended
Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Federal corporate statutory rate	35.00%	35.00%	35.00%
State and local, net of Federal benefits	2.40%	2.00%	1.20%
Foreign	(0.10%)	(1.00%)	(1.50%)
Research credit	(1.10%)	(2.50%)	(1.80%)
Domestic production deduction	(2.70%)	(2.80%)	(2.60%)
Change in uncertain tax positions	0.00%	0.00%	(0.20%)
Executive compensation	(0.10%)	0.90%	0.90%
Valuation allowance	(0.30%)	1.80%	1.00%
Other, net	(0.10%)	(0.50%)	0.20%
Effective income tax rate	33.00%	32.90%	32.20%

Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32698-109319

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to changes in the valuation allowance for deferred tax assets.

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations applicable to statutory income tax expense (benefit) outside of the country of domicile.

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations applicable to state and local income tax expense (benefit), net of federal tax expense (benefit).

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to income tax contingencies. Includes, but not limited to, domestic tax contingency, foreign tax contingency, state and local tax contingency, and other contingencies.

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