Long-Term Investments - Long-Term Investments (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]
Equity-method investments	$ 56us-gaap_EquityMethodInvestments	$ 63us-gaap_EquityMethodInvestments
Cost-method investments	13us-gaap_CostMethodInvestments	13us-gaap_CostMethodInvestments
Total	$ 69us-gaap_LongTermInvestments	$ 76us-gaap_LongTermInvestments

Amount, after adjustment, of cost-method investment. Adjustments include, but are not limited to, dividends received in excess of earnings after date of investment that are considered a return of investment and other than temporary impairments.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.12)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 325

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6872867&loc=d3e40691-111596

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 325

-SubTopic 20

-Section 35

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=29638308&loc=d3e40346-111594

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- Definition

This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

+ References

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Data Type:	xbrli:monetaryItemType
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- Definition

The total amount of investments that are intended to be held for an extended period of time (longer than one operating cycle).

+ References

+ Details

Name:	us-gaap_LongTermInvestments
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

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