Intangible Assets (Schedule of Finite-Lived Intangible Assets by Major Class) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Finite-Lived Intangible Assets
Net finite-lived intangible assets, beginning of period	$ 682us-gaap_FiniteLivedIntangibleAssetsNet	$ 712us-gaap_FiniteLivedIntangibleAssetsNet
Amortization	(108)us-gaap_AmortizationOfIntangibleAssets	(30)us-gaap_AmortizationOfIntangibleAssets
Net finite-lived intangible assets, end of period	3,439us-gaap_FiniteLivedIntangibleAssetsNet	682us-gaap_FiniteLivedIntangibleAssetsNet
Finite-Lived Intangible Assets, Future Amortization
Intangible Assets Acquired	(2,865)
2015	135
2016	135
2017	135
2018	135
2019	135
Customer Relations
Finite-Lived Intangible Assets
Net finite-lived intangible assets, beginning of period	629	655
Amortization	(105)	26
Net finite-lived intangible assets, end of period	3,389	629
Finite-Lived Intangible Assets, Future Amortization
Average remaining amortization periods, years	28 years 0 months 0 days
Intangible Assets Acquired	(2,865)
Trade Names
Finite-Lived Intangible Assets
Net finite-lived intangible assets, beginning of period	53	57
Amortization	(3)	4
Net finite-lived intangible assets, end of period	50	53
Finite-Lived Intangible Assets, Future Amortization
Average remaining amortization periods, years	15 years 0 months 0 days
Intangible Assets Acquired	$ 0

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 45

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-URI http://asc.fasb.org/extlink&oid=6388964&loc=d3e16225-109274

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

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-Name Accounting Standards Codification

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

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

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

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Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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