Income Taxes - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	9 Months Ended
Sep. 30, 2013 issue
Income Taxes [Line Items]
Number of unresolved issues related to IRS income tax examination for 2010	1
Unrecognized tax benefits	$ 29
Unrecognized tax benefits that, if recognized, would impact the effective tax rate	13
Income tax expense (benefit) recognized due to retroactive provisions in American Taxpayer Relief Act of 2012	(3)
International Issue Relating to Financing Activity
Income Taxes [Line Items]
Unrecognized tax benefits	$ 5

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Income Tax Examination, Number of Unresolved Issues

+ References

No definition available.

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- Definition

Amount of increase (decrease) to previously recorded tax expense. Includes, but is not limited to, significant settlements of income tax disputes, and unusual tax positions or infrequent actions taken by the entity, including tax assessment reversal, and IRS tax settlement.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 25

-Paragraph 8

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

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-Paragraph 10

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- Definition

Amount of unrecognized tax benefits pertaining to uncertain tax positions taken in tax returns.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Unrecognized Tax Benefit

-URI http://asc.fasb.org/extlink&oid=6527854

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-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 10

-Section 50

-Paragraph 15A

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The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 15A

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