Pensions and Post Retirement Benefits Other Than Pensions - Weighted Average Asset Allocations for Domestic and U.K. Pension Plans' Assets (Detail)	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011
United States plan [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Equity securities	58.00%	61.00%
Debt securities	40.00%	37.00%
Other investments	0.00%	0.00%
Cash	2.00%	2.00%
Total	100.00%	100.00%
United Kingdom plan [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Equity securities	59.00%	56.00%
Debt securities	28.00%	29.00%
Other investments	12.00%	14.00%
Cash	1.00%	1.00%
Total	100.00%	100.00%

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.

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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