Consolidated Statements of Equity (Unaudited) (Parenthetical) (USD $) In Millions, unless otherwise specified	9 Months Ended
Sep. 30, 2012	Sep. 30, 2013 Maximum [Member]
Net Income (Loss) Attributable to Redeemable Noncontrolling Interest	$ 5	$ 1

Amount of Net Income (Loss) attributable to redeemable noncontrolling interest.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.19)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration