Capital Lease Payments Over Next Five Years (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011
Schedule of Capital Lease Obligations [Line Items]
2012	$ 14
2013	11
2014	4
2015	2
2016	$ 0

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Contractually required rental payments on leases meeting the criteria for capitalization, due within one year of the balance sheet date.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 13

-Paragraph 16

-Subparagraph a(ii)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 840

-SubTopic 30

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6455398&loc=d3e45280-112737

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- Definition

Contractually required rental payments on leases meeting the criteria for capitalization, due within the fifth year from the balance sheet date.

+ References

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- Definition

Contractually required rental payments on leases meeting the criteria for capitalization, due within the fourth year from the balance sheet date.

+ References

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Contractually required rental payments on leases meeting the criteria for capitalization, due within the third year from the balance sheet date.

+ References

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Contractually required rental payments on leases meeting the criteria for capitalization, due within the second year from the balance sheet date.

+ References

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