Schedule II (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Valuation And Qualifying Accounts Disclosure [Line Items]
Valuation Allowances and Reserves, Balance	$ 119	$ 116	$ 125	$ 110
Net (credits) charges to expenses	14	11	27
Valuation Allowances and Reserves, Deductions	7	13	15
Valuation Allowances and Reserves, Charged to Other Accounts	$ (4)	$ (7)	$ 3

Total of allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs.

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 09

-Article 12

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e24092-122690

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