Income Taxes (Unrecognized Tax Benefits) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at January 1,	$ 128us-gaap_UnrecognizedTaxBenefits	$ 117us-gaap_UnrecognizedTaxBenefits	$ 143us-gaap_UnrecognizedTaxBenefits
Additions, based on tax positions related to current year	13	16	26
Additions for tax positions of prior years	3	35	35
Reductions for tax positions of prior years	(29)	(7)	(41)
Settlements	(4)	(3)	(6)
Lapses in statutes of limitation	(14)	(30)	(40)
Balance at December 31,	$ 97us-gaap_UnrecognizedTaxBenefits	$ 128us-gaap_UnrecognizedTaxBenefits	$ 117us-gaap_UnrecognizedTaxBenefits

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Amount of unrecognized tax benefits pertaining to uncertain tax positions taken in tax returns.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

-Glossary Unrecognized Tax Benefit

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Amount of decrease 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 settlements with taxing authorities.

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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.

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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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