Income Taxes (Details 4) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012 Potential settlements with certain states and foreign countries
Reasonably possible decrease in unrecognized tax benefits liability within the next twelve months
Reasonably possible decrease in uncertain income tax liabilities within the next twelve months	$ 138	$ 126

The amount of the unrecognized tax benefit of a position taken for which it is reasonably possible that the total amount thereof will significantly increase or decrease within twelve months of the balance sheet date.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 15

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32718-109319

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

-Publisher FASB

-Name FASB Interpretation (FIN)

-Number 48

-Paragraph 21

-Subparagraph d

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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