|**Employee Retirement Benefits**                      | 3 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
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|**Compensation and Retirement Disclosure [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
|Employee Retirement Benefits                          | EMPLOYEE RETIREMENT BENEFITSThe following summarizes the components of net periodic costs for our qualified and supplemental pension plans:(In millions)Three months ended March 31,20142013Service cost$2$3Interest cost43Expected return on plan assets(4)(4)Amortization of actuarial loss and prior service cost12Net periodic benefit cost$3$4See our 2013 Annual Report on Form 10-K, Item 8, Note 13, Employee Retirement Benefits, Page 148, for information on our retirement benefits. We made matching contributions of$4 millionand$3 millionto our401(k) and Top Hat savings plans during the first quarters of 2014 and 2013.We contributed$5 millionto our qualified pension plan during the first quarter of 2014. We do not anticipate further contributions to our qualified pension plan during the remainder of 2014.
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|(In millions)                                         |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
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|Service cost                                          |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
|Interest cost                                         |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
|Expected return on plan assets                        |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
|Amortization of actuarial loss and prior service cost |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
|Net periodic benefit cost                             |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
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