| **Fair Value Measurements (Details) - USD ($) $ in Millions** | Dec. 31, 2016 | Dec. 31, 2015 |
|---------------------------------------------------------------|---------------|---------------|
| Recurring basis | Level 2                                     |          |          |
| **Assets**                                                    |          |          |
| Derivative financial instruments, net                         | $ 64          | $ 81          |

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| - References
No definition available.
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| - Definition
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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