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Commitments and Contingencies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013 site Plaintiff Cases
Environmental Remediation Obligations [Abstract]
Liable cases	100
Liable periods	20 years
Accrued environmental obligations approximately	$ 48
Sites associated with remediation	50
Remediation and related matters possible to estimate costs	$ 139
Currently not able to estimate a range of costs to sites	5
Number of cases pending	1,125
Number of Plaintiffs Involved in Pending Cases	1,643
Number of cases administratively dismissed or inactive	8,298

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- Definition

Litigation matter cases in which company not been found liable numbers.

+ References

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Litigation matter cases in which company not been found liable period.

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- Definition

Number of environmental sites with no estimate.

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- Definition

Number of plaintiffs have been administratively dismissed or placed on inactive docket.

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Number of plaintiffs involved.

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- Definition

Number of sites associated to accrual for environmental remediation.

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- Definition

Upper range of environmental loss estimate.

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- Definition

Present value of the accrual for environmental loss contingencies.

+ References

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

-Publisher AICPA

-Name Statement of Position (SOP)

-Number 96-1

-Paragraph 161, 132

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 450

-SubTopic 20

-Section S99

-Paragraph 1

-Subparagraph (SAB TOPIC 5.Y.Q1)

-URI http://asc.fasb.org/extlink&oid=6572457&loc=d3e149879-122751



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

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 5

-Section Y

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 410

-SubTopic 30

-Section 50

-Paragraph 7

-URI http://asc.fasb.org/extlink&oid=6393242&loc=d3e13207-110859

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The number of claims settled and dismissed during the period.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 5

-Paragraph 9, 10, 11, 12

-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.

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