| **Fair Value Measurements and Disclosures (Details 3) (USD $)In Millions, unless otherwise specified** | Sep. 30, 2013 | Dec. 31, 2012 |
|--------------------------------------------------------------------------------------------------------|---------------|---------------|
| Carrying Amount                                                                                        |          |               |   |  |
| **Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]**                      |          |               |   |  |
| Long Term Debt Net Of Unamortized Discount                                                             | $ 4,273       | [1]           | $ 3,797 | [1] |
| Fair Value                                                                                             |          |               |   |  |
| **Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]**                      |          |               |   |  |
| Long Term Debt Net Of Unamortized Discount                                                             | $ 4,778       | [1]           | $ 4,570 | [1] |
|                                                                                                        |
| [1]) Excludes FPSO and other capital lease obligations.                                           |

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| - Details**Name:**us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
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| - Definition
The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.
+ References
No definition available.
+ Details**Name:**us-gaap_LongTermDebtFairValue**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |