Fair Value Measurements (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Level 3
Liabilities
Guarantees	$ 1	$ 1	$ 2
Fair Value, Measurements, Recurring
Assets
Derivative financial instruments, net	78	128	223
Total Assets	78	128	223
Liabilities
Guarantees	1	1	2
Total liabilities	1	1	2
Fair Value, Measurements, Recurring \| Level 1
Assets
Derivative financial instruments, net	0	0	0
Total Assets	0	0	0
Liabilities
Guarantees	0	0	0
Total liabilities	0	0	0
Fair Value, Measurements, Recurring \| Level 2
Assets
Derivative financial instruments, net	78	128	223
Total Assets	78	128	223
Liabilities
Guarantees	0	0	0
Total liabilities	0	0	0
Fair Value, Measurements, Recurring \| Level 3
Assets
Derivative financial instruments, net	0	0	0
Total Assets	0	0	0
Liabilities
Guarantees	1	1	2
Total liabilities	$ 1	$ 1	$ 2

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

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Fair values as of the balance sheet date of the net amount of all assets and liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 45

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41228-113958

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Fair value portion of guarantee, including, but not limited to, financial standby letter of credit, fair value guarantee, guarantee of collection of scheduled contractual cash flows from financial assets, and contracts that contingently require the guarantor to make payments or perform services.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 460

-SubTopic 10

-Section 50

-Paragraph 5

-Subparagraph (a)

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Fair value of financial and nonfinancial obligations.

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