| **Capitalized Exploratory Well Costs (Details) (USD $)In Millions, unless otherwise specified**                                             | 6 Months Ended |        |
|---------------------------------------------------------------------------------------------------------------------------------------------|----------------|--------|
||
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Capitalized Exploratory Well Costs, Beginning of Period                                                                                     | $ 1,301        |   |
| Additions to Capitalized Exploratory Well Costs Pending Determination of Proved Reserves                                                    | 195            |   |
| Reclassified to Proved Oil and Gas Properties Based on Determination of Proved Reserves                                                     | (80)           |   |
| Capitalized Exploratory Well Cost, Charged to Expense                                                                                       | (2)            |   |
| Capitalized Exploratory Well Costs, End of Period                                                                                           | 1,414          |   |
| Exploratory Well Costs capitalized for a Period of One Year or Less                                                                         | 517            | 568    |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 897            | 733    |
| Capitalized Exploratory Well Costs, End of Period                                                                                           | 1,414          |   |
| Number of Projects with Exploratory Well Costs That Have Been Capitalized for a Period Greater Than One Year Since Commencement of Drilling | 13             | 13     |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 897            | 733    |
| 2012 - 2013                                                                                                                                 |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 437            |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 437            |   |
| 2010 - 2011                                                                                                                                 |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 304            |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 304            |   |
| 2009 & Prior                                                                                                                            |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 156            |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 156            |   |
| Diega (including Carmen) Offshore Equatorial Guinea [Member]                                                                                |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 111            |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 111            |   |
| Diega (including Carmen) Offshore Equatorial Guinea [Member] | 2012 - 2013                                                                  |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 6              |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 6              |   |
| Diega (including Carmen) Offshore Equatorial Guinea [Member] | 2010 - 2011                                                                  |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 52             |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 52             |   |
| Diega (including Carmen) Offshore Equatorial Guinea [Member] | 2009 & Prior                                                             |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 53             |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 53             |   |
| Carla Offshore Equatorial Guinea [Member]                                                                                                   |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 149            |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 149            |   |
| Carla Offshore Equatorial Guinea [Member] | 2012 - 2013                                                                                     |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 137            |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 137            |   |
| Carla Offshore Equatorial Guinea [Member] | 2010 - 2011                                                                                     |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 12             |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 12             |   |
| Carla Offshore Equatorial Guinea [Member] | 2009 & Prior                                                                                |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 0              |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 0              |   |
| Felicita Offshore Equatorial Guinea [Member]                                                                                                |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 38             |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 38             |   |
| Felicita Offshore Equatorial Guinea [Member] | 2012 - 2013                                                                                  |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 3              |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 3              |   |
| Felicita Offshore Equatorial Guinea [Member] | 2010 - 2011                                                                                  |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 6              |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 6              |   |
| Felicita Offshore Equatorial Guinea [Member] | 2009 & Prior                                                                             |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 29             |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 29             |   |
| Yolanda Offshore Equatorial Guinea [Member]                                                                                                 |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 19             |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 19             |   |
| Yolanda Offshore Equatorial Guinea [Member] | 2012 - 2013                                                                                   |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 2              |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 2              |   |
| Yolanda Offshore Equatorial Guinea [Member] | 2010 - 2011                                                                                   |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 3              |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 3              |   |
| Yolanda Offshore Equatorial Guinea [Member] | 2009 & Prior                                                                              |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 14             |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 14             |   |
| YoYo Offshore Cameron [Member]                                                                                                              |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 46             |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 46             |   |
| YoYo Offshore Cameron [Member] | 2012 - 2013                                                                                                |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 3              |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 3              |   |
| YoYo Offshore Cameron [Member] | 2010 - 2011                                                                                                |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 9              |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 9              |   |
| YoYo Offshore Cameron [Member] | 2009 & Prior                                                                                           |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 34             |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 34             |   |
| Leviathan Offshore Israel [Member]                                                                                                          |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 180            |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 180            |   |
| Leviathan Offshore Israel [Member] | 2012 - 2013                                                                                            |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 70             |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 70             |   |
| Leviathan Offshore Israel [Member] | 2010 - 2011                                                                                            |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 110            |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 110            |   |
| Leviathan Offshore Israel [Member] | 2009 & Prior                                                                                       |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 0              |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 0              |   |
| Leviathan-1 Deep Offshore Israel [Member]                                                                                                   |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 76             |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 76             |   |
| Leviathan-1 Deep Offshore Israel [Member] | 2012 - 2013                                                                                     |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 49             |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 49             |   |
| Leviathan-1 Deep Offshore Israel [Member] | 2010 - 2011                                                                                     |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 27             |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 27             |   |
| Leviathan-1 Deep Offshore Israel [Member] | 2009 & Prior                                                                                |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 0              |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 0              |   |
| Dalit Offshore Israel [Member]                                                                                                              |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 25             |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 25             |   |
| Dalit Offshore Israel [Member] | 2012 - 2013                                                                                                |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 3              |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 3              |   |
| Dalit Offshore Israel [Member] | 2010 - 2011                                                                                                |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 2              |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 2              |   |
| Dalit Offshore Israel [Member] | 2009 & Prior                                                                                           |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 20             |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 20             |   |
| Dolphin 1 Offshore Israel [Member]                                                                                                          |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 24             |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 24             |   |
| Dolphin 1 Offshore Israel [Member] | 2012 - 2013                                                                                            |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 2              |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 2              |   |
| Dolphin 1 Offshore Israel [Member] | 2010 - 2011                                                                                            |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 22             |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 22             |   |
| Dolphin 1 Offshore Israel [Member] | 2009 & Prior                                                                                       |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 0              |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 0              |   |
| Cyprus [Member]                                                                                                                             |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 109            |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 109            |   |
| Cyprus [Member] | 2012 - 2013                                                                                                               |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 52             |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 52             |   |
| Cyprus [Member] | 2010 - 2011                                                                                                               |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 57             |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 57             |   |
| Cyprus [Member] | 2009 & Prior                                                                                                          |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 0              |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 0              |   |
| Scotia Falkland Islands [Member]                                                                                                            |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 71             |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 71             |   |
| Scotia Falkland Islands [Member] | 2012 - 2013                                                                                              |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 71             |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 71             |   |
| Scotia Falkland Islands [Member] | 2010 - 2011                                                                                              |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 0              |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 0              |   |
| Scotia Falkland Islands [Member] | 2009 & Prior                                                                                         |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 0              |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 0              |   |
| Other - Projects of $20 million or less each [Member]                                                                                       |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 49             |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 49             |   |
| Other - Projects of $20 million or less each [Member] | 2012 - 2013                                                                         |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 39             |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 39             |   |
| Other - Projects of $20 million or less each [Member] | 2010 - 2011                                                                         |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 4              |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 4              |   |
| Other - Projects of $20 million or less each [Member] | 2009 & Prior                                                                    |           |   |
| **Capitalized Exploratory Well Costs [Abstract]**                                                                                           |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | 6              |   |
| **Projects with Exploratory Well Costs Capitalized for More than One Year Since The Commencement of Drilling [Line Items]**                 |           |   |
| Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling                                        | $ 6            |   |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Additions to capitalized exploratory well costs that were added during the reporting period pending the determination of proved reserves.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 1B -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=8451039&loc=SL6806780-109447
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Capitalized exploratory well costs that were expensed during the year because proved reserves were not found at the exploratory well.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 1B -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=8451039&loc=SL6806780-109447
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The amount of capitalized exploratory well costs that is pending the determination of proved reserves. This does not include amounts that were capitalized and subsequently expensed in the same annual period.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 1B -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=8451039&loc=SL6806780-109447
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The amount of exploratory well costs that have been capitalized for a period of greater than one year after the completion of drilling.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 1B -Subparagraph b -URI http://asc.fasb.org/extlink&oid=8451039&loc=SL6806780-109447
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The amount of exploratory well costs that have been capitalized for a period of one year or less after the completion of drilling.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 16 -URI http://asc.fasb.org/extlink&oid=8451039&loc=d3e61939-109447
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The number of projects for which exploratory well costs have been capitalized for a period of greater than one year after the completion of drilling.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 1B -Subparagraph b -URI http://asc.fasb.org/extlink&oid=8451039&loc=SL6806780-109447
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|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Previously capitalized costs of the drilling of wells that were reclassified as part of the costs of the enterprise's wells and related equipment and facilities at the time that proved reserves were found.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 1B -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=8451039&loc=SL6806780-109447
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