| **Benefit Plans**                                     | 9 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
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| **Compensation and Retirement Disclosure [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| Benefit Plans                                         | Note I. 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)2012 2011 2012 2011Pension cost (benefit)       Service cost$3 $3 $9 $10Interest cost on projected benefit obligation34 37 101 110Expected return on plan assets(43) (44) (128) (130)Amortization of net actuarial (gain) loss10 7 29 19Net periodic pension cost (benefit)$4 $3 $11 $9        Postretirement cost (benefit)       Interest cost on projected benefit obligation$1 $1 $2 $3Amortization of prior service credit(4) (5) (13) (14)Net periodic postretirement cost (benefit)$(3) $(4) $(11) $(11) |

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