Income Taxes (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
Reconciliation of actual income tax expenses (benefits)
Provision for U.S. federal income tax at statutory rate	$ 18,153	$ 15,617	$ 7,313
Effect of foreign income taxes	(140)	(244)	(19)
Manufacturers'/producers' deduction	(1,868)	(921)	(504)
Research and experimentation tax credits	(99)	(750)	(27)
State income taxes, net of federal income tax benefit	240	181	139
Nondeductible expenses	165	504	197
Resolution of prior years' tax matters	544	(116)	(121)
Contingency for uncertainty in income taxes	(335)	632	(123)
Other items	84	5	(35)
Income tax expense	$ 16,744	$ 14,908	$ 6,820
Company's effective tax rates	32.30%	33.40%	32.60%

A ratio calculated by dividing the reported amount of income tax expense attributable to continuing operations for the period by GAAP-basis pretax income from continuing operations.

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The sum of the current income tax expense or benefit and the deferred income tax expense or benefit pertaining to continuing operations.

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The portion of the difference between total income tax expense or benefit as reported in the Income Statement for the period and the expected income tax expense or benefit computed by applying the domestic federal statutory income tax rates to pretax income from continuing operations attributable to the deduction for qualified production activities received under enacted tax laws.

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The portion of the difference, between total income tax expense or benefit as reported in the Income Statement for the period and the expected income tax expense or benefit computed by applying the domestic federal statutory income tax rates to pretax income from continuing operations, that is attributable to total foreign income tax expense or benefit. The foreign income tax expense or benefit difference represents the income tax expense or benefit at applicable domestic statutory income tax rates applied to foreign earnings or loss for the period versus the foreign income tax expense or benefit calculated by applying the appropriate foreign tax rates.

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The portion of the difference between total income tax expense or benefit as reported in the Income Statement for the current period and the expected income tax expense or benefit computed attributable to revisions of previously reported income tax expense.

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