Asset Allocation Ranges and Actual Allocation, USRIP (Detail) (U.S. Retirement Income Plan, or USRIP)	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011
Large-Cap Equity
Defined Benefit Plan Disclosure [Line Items]
Range minimum	10.00%
Range maximum	35.00%
Actual	19.10%	13.90%
Small- and Mid-Cap Equity
Defined Benefit Plan Disclosure [Line Items]
Range minimum	0.00%
Range maximum	15.00%
Actual	4.00%	1.30%
International Equity
Defined Benefit Plan Disclosure [Line Items]
Range minimum	10.00%
Range maximum	30.00%
Actual	16.70%	10.70%
Private Equity
Defined Benefit Plan Disclosure [Line Items]
Range minimum	2.00%
Range maximum	10.00%
Actual	7.30%	6.20%
Hedge Funds
Defined Benefit Plan Disclosure [Line Items]
Range minimum	10.00%
Range maximum	30.00%
Actual	18.00%	17.30%
Real Assets
Defined Benefit Plan Disclosure [Line Items]
Range minimum	2.00%
Range maximum	10.00%
Actual	5.90%	5.20%
Fixed Income
Defined Benefit Plan Disclosure [Line Items]
Range minimum	15.00%
Range maximum	40.00%
Actual	27.50%	34.80%
Cash
Defined Benefit Plan Disclosure [Line Items]
Range minimum	0.00%
Range maximum	15.00%
Actual	1.50%	10.60%

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Target allocation maximum percentage of investments of this type to total plan assets presented on a weighted average basis.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (d)(i)

-URI http://asc.fasb.org/extlink&oid=21915506&loc=d3e1928-114920

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 5

-Subparagraph (c)(i)

-URI http://asc.fasb.org/extlink&oid=21915506&loc=d3e2446-114920

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- Definition

Target allocation minimum percentage of investments of this type to total plan assets presented on a weighted average basis.

+ References

+ Details

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- Definition

Percentage of fair value of investments (categorized by debt securities, equity securities, real estate and other plan assets) to the fair value of plan assets held.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 5

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=21915506&loc=d3e2446-114920

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (d)(1)

-URI http://asc.fasb.org/extlink&oid=21915506&loc=d3e1928-114920

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 5

-Subparagraph d(1)

-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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