Allowance for Doubtful Accounts Activity (Detail) (Allowance for Doubtful Accounts, USD $) In Thousands	12 Months Ended
Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2009
Allowance for Doubtful Accounts
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	$ 491	$ 719	$ 1,366
Provisions		125	419
Reversals of Bad Debt Expense		(192)
Write-offs and Adjustments	126	(161)	(1,066)
Balance at End of Period	$ 617	$ 491	$ 719

Valuation Allowances and Reserves, Deductions/Recoveries

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- Definition

Valuation Allowances and Reserves, Deductions, Write Offs, and Other

+ Details

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- Definition

Total of the adjustments in a given period to allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 09

-Article 12

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e24092-122690

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- Definition

Total of allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs.

+ References

+ Details

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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