Debt - Amount of Debt Due in Next Five Years - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013
Debt Disclosure [Abstract]
Debt due in 2014	$ 229
Debt due in 2015	0
Debt due in 2016	250
Debt due in 2017	0
Debt due in 2018	0
Debt due thereafter 2019	$ 753

Name:	us-gaap_DebtDisclosureAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Amount of long-term debt of the registrant maturing in the third fiscal year following the latest fiscal year.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 3

-Subparagraph (SX 210.12-04.(a))

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24072-122690

+ Details

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Period Type:	instant

- Definition

Amount of long-term debt of the registrant maturing after the fifth fiscal year following the latest fiscal year.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of long-term debt of the registrant maturing in the fifth fiscal year following the latest fiscal year.

+ References

+ Details

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Period Type:	instant

- Definition

Amount of long-term debt of the registrant maturing in the fourth fiscal year following the latest fiscal year.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

- Definition

Amount of long-term debt of the registrant maturing in the second fiscal year following the latest fiscal year.

+ References

+ Details

Name:	us-gaap_FiveYearScheduleOfMaturitiesOfParentCompanyRepaymentsOfPrincipleInYearTwo
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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

- Definition

Amount of long-term debt of the registrant maturing in the next fiscal year following the latest fiscal year.

+ References

+ Details

Name:	us-gaap_FiveYearScheduleOfMaturitiesOfParentCompanyRepaymentsOfPrincipleWithinOneYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant