|**Income Taxes**                     | 9 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            
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|**Income Tax Disclosure [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
|Income Taxes                         | Income TaxesThe income tax provision relating to continuing operations consists of the following:Three Months Ended September 30,Nine Months EndedSeptember 30,(millions)2015201420152014Current$(45)$120$64$213Deferred6937(244)61Total Income Tax (Benefit) Provision$24$157$(180)$274Effective Tax Rate(9.3)%27.2%30.4%25.3%At the end of each interim period, we apply our best estimate of our effective tax rate (ETR) expected to be applicable for the full year, which can result in interim ETR fluctuations. Our ETR for the three andninemonths endedSeptember 30, 2015varied as compared with the three andninemonths endedSeptember 30, 2014primarily as a result of a tax benefit. In the case of a pre-tax loss, our favorable permanent differences, such as income from equity method investees and increased earnings in our foreign jurisdictions with rates that vary from the US statutory rate, have the effect of increasing the tax benefit which, in turn, increases the ETR.In our major tax jurisdictions, the earliest years remaining open to examination are as follows: US –2012, Equatorial Guinea –2010and Israel –2010.
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|                                     | Three Months Ended September 30,                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
|(millions)                           | 2015                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
|Current                              | $                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Deferred                             | 69                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        
|Total Income Tax (Benefit) Provision | $                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Effective Tax Rate                   | (9.3                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      

X- ReferencesNo definition available.
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duration X- DefinitionThe entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.
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