| **Benefit Plans (Schedule of amounts recognized in Other comprehensive income) (Details) - USD ($) $ in Millions**                        | 12 Months Ended |
|-------------------------------------------------------------------------------------------------------------------------------------------|-----------------|
||
| **Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, before Tax, [Abstract]**                 |            |   |   |
| Amounts arising during the period                                                                                                         | $ (29)          | $ (111) | $ (337) |
| Curtailment and other                                                                                                                     | 0               | 56 | (81) |
| Settlement through group annuity purchase                                                                                                 | 0               | 0 | 84 |
| Reclassification adjustment relating to prior service cost (credit)                                                                       | (2)             | (3) | (10) |
| Reclassification adjustment relating to actuarial (gain) loss                                                                             | 37              | 35 | 26 |
| Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Settlements Through Group Annuity Purchase, before Tax | (2)             | 0 | 0 |
| Total increase (decrease) in Other comprehensive income                                                                                   | $ 4             | $ (23) | $ (318) |

| X                                                                                                                                                                                                                                                                                                                                                                   |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Other Comprehensive Income (Loss) Curtailment and the related Plan Amendment
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Settlements Through Group Annuity Purchase, before Tax
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                         |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Settlements, before Tax
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                      |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - References
No definition available.
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|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount before tax of reclassification adjustment from accumulated other comprehensive (income) loss for prior service cost (credit) related to pension and other postretirement benefit plans.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount before tax, after reclassification adjustments, of (increase) decrease in accumulated other comprehensive (income) loss related to pension and other postretirement defined benefit plans.
+ References
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|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount before tax of (increase) decrease in the value of the projected benefit obligation related to a change in an actuarial assumption and increase (decrease) in the value of the plan assets resulting from experience different from that assumed, that has not been recognized in net periodic benefit (cost) credit.
+ References
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|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount before tax of reclassification adjustment from accumulated other comprehensive income (loss) for actuarial gain (loss) related to pension and other postretirement benefit plans.
+ References
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