| **Benefit Plans**                                     | 9 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
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| **Compensation and Retirement Disclosure [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| Benefit Plans                                         | Note H. Benefit PlansThe components of net periodic cost (benefit) are presented in the following table.Net Periodic Cost (Benefit)Periods ended September 30Three Months Nine Months(In millions)2013 2012 2013 2012Pension cost (benefit)       Service cost$3 $3 $9 $9Interest cost on projected benefit obligation30 34 90 101Expected return on plan assets(45) (43) (135) (128)Amortization of net actuarial (gain) loss10 10 34 29Settlement loss3 — 3 —Net periodic pension cost (benefit)$1 $4 $1 $11        Postretirement cost (benefit)       Interest cost on projected benefit obligation$— $1 $1 $2Amortization of prior service credit(4) (4) (13) (13)Amortization of net actuarial (gain) loss1 — 1 —Net periodic postretirement cost (benefit)$(3) $(3) $(11) $(11) |

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