| **Employee Retirement Benefits**                      | 3 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
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| **Compensation and Retirement Disclosure [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
| Employee Retirement Benefits                          | EMPLOYEE RETIREMENT BENEFITS The following summarizes the components of net periodic costs for our qualified and supplemental pension plans:(In millions) Three months ended March 31,  2013 2012Service cost $3 $3Interest cost 3 3Expected return on plan assets (4) (4)Amortization of actuarial loss and prior service cost 2 2Net periodic benefit cost $4 $4See our 2012 Annual Report on Form 10-K, Item 8, Note 13, Employee Retirement Benefits, Page 130, for information on our retirement benefits. We made matching contributions of $3 million and $2 million to our 401(k) and Top Hat savings plans during the first quarters of 2013 and 2012, respectively.    We contributed $15 million to our qualified pension plan during the first quarter of 2013. We do not anticipate further contributions to our qualified pension plan during the remainder of 2013. |

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| - Definition
The entire disclosure for pension and other postretirement benefits.
+ References
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