Derivative Financial Instruments - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Dec. 31, 2012	Dec. 31, 2012 Foreign currency forward contracts	Sep. 30, 2012 Foreign currency forward contracts
Derivative [Line Items]
Short-term forward contracts, average maturities at inception	3 months
Forward foreign currency contracts fair value		$ 0	$ 0

Fair value of the assets less the liabilities of a derivative or group of derivatives.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 45

-Paragraph 6

-URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41271-113958

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

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-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=7491637&loc=d3e13433-108611

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 45

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-URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41228-113958

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

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-Section 50

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-URI http://asc.fasb.org/extlink&oid=7491637&loc=d3e13495-108611

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant