| **Benefit Plans**                                     | 6 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 June 30Three Months Six Months(In millions)2012 2011 2012 2011Pension cost (benefit)       Service cost$3 $3 $6 $7Interest cost on projected benefit obligation33 36 67 73Expected return on plan assets(42) (43) (85) (86)Amortization of net actuarial (gain) loss9 6 19 12Net periodic pension cost (benefit)$3 $2 $7 $6        Postretirement cost (benefit)       Interest cost on projected benefit obligation$1 $1 $1 $2Amortization of prior service credit(5) (4) (9) (9)Amortization of net actuarial (gain) loss— (1) — —Net periodic postretirement cost (benefit)$(4) $(4) $(8) $(7) |

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