Notional Values of Derivative Instruments (Detail)	Jun. 30, 2012
Derivative [Line Items]
Notional Value of Copper Derivatives	70

Aggregate notional amount of price risk derivatives designated as a cash flow hedge with notional amounts expressed in nonmonetary units. For example the number of barrels specified in a fuel oil forward purchase contract.

Reference 1: 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=7476318&loc=SL5579245-113959

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Notional Amount

-URI http://asc.fasb.org/extlink&oid=6519104

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4B

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624163-113959

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