- Reconciliation of our Uncertain Tax Positions (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Uncertain tax positions -
Balance January 1	$ 115us-gaap_UnrecognizedTaxBenefits	$ 107us-gaap_UnrecognizedTaxBenefits	$ 119us-gaap_UnrecognizedTaxBenefits
Gross increases in tax positions in current period	8	15	13
Gross increases in tax positions in prior period	5	0	1
Gross decreases in tax positions in prior period	(5)	(1)	(12)
Gross decreases - settlements	(2)	0	(5)
Gross decreases - statute of limitations expired	(7)	(6)	(9)
Balance December 31	$ 114us-gaap_UnrecognizedTaxBenefits	$ 115us-gaap_UnrecognizedTaxBenefits	$ 107us-gaap_UnrecognizedTaxBenefits

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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

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

-Publisher FASB

-Name Accounting Standards Codification

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-Section 50

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Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

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-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=6907707&loc=SL6600010-109319

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Amount of decrease in unrecognized tax benefits resulting from settlements with taxing authorities.

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

-Publisher FASB

-Name Accounting Standards Codification

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Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return.

+ References

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

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Amount of increase in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

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Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations.

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

-Publisher FASB

-Name Accounting Standards Codification

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