Hedging Transactions and Derivative Financial Instruments - Additional Information (Detail)	Mar. 31, 2012 Contract
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Number of derivative contracts related to minimizing risk associated with potential rise in copper prices	2
Number of derivative contracts related to minimizing foreign currency exposures	1

Number of foreign currency exchange rate derivatives held by the entity at the reporting date.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 44

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 1B

-URI http://asc.fasb.org/extlink&oid=6935481&loc=SL5580258-113959

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 1A

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=6935481&loc=SL5579245-113959

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Data Type:	xbrli:integerItemType
Balance Type:	na
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