| **Benefit Plans (Estimated Future Minimum Benefit Payments to Participants) (Details) (USD $)In Millions, unless otherwise specified** | Dec. 31, 2013 |
|----------------------------------------------------------------------------------------------------------------------------------------|---------------|
| Pension Plans, Defined Benefit [Member]                                                                                                |          |
| **Defined benefit plan disclosure [Line items]**                                                                                       |          |
| Defined Benefit Plan, Expected Future Benefit Payments in Year One                                                                     | $ 189         |
| Defined Benefit Plan, Expected Future Benefit Payments in Year Two                                                                     | 191           |
| Defined Benefit Plan, Expected Future Benefit Payments in Year Three                                                                   | 194           |
| Defined Benefit Plan, Expected Future Benefit Payments in Year Four                                                                    | 199           |
| Defined Benefit Plan, Expected Future Benefit Payments in Year Five                                                                    | 203           |
| Defined Benefit Plan, Expected Future Benefit Payments in Five Fiscal Years Thereafter                                                 | 1,013         |
| Other Postretirement Benefit Plan, Defined Benefit [Member]                                                                            |          |
| **Defined benefit plan disclosure [Line items]**                                                                                       |          |
| Defined Benefit Plan, Expected Future Benefit Payments in Year One                                                                     | 5             |
| Defined Benefit Plan, Expected Future Benefit Payments in Year Two                                                                     | 4             |
| Defined Benefit Plan, Expected Future Benefit Payments in Year Three                                                                   | 5             |
| Defined Benefit Plan, Expected Future Benefit Payments in Year Four                                                                    | 4             |
| Defined Benefit Plan, Expected Future Benefit Payments in Year Five                                                                    | 4             |
| Defined Benefit Plan, Expected Future Benefit Payments in Five Fiscal Years Thereafter                                                 | $ 14          |

| X                                                                                                                                                                         |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of benefits expected to be paid  in the five fiscal years after the fifth fiscal year following the latest fiscal year from a defined benefit plan.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of benefits expected to be paid in the next fiscal year following the latest fiscal year from a defined benefit plan.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of benefits expected to be paid in the fifth fiscal year following the latest fiscal year from a defined benefit plan.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of benefits expected to be paid in the fourth fiscal year following the latest fiscal year from a defined benefit plan.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
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| - Definition
Amount of benefits expected to be paid in the third fiscal year following the latest fiscal year from a defined benefit plan.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
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| - Definition
Amount of benefits expected to be paid in the second fiscal year following the latest fiscal year from a defined benefit plan.
+ References
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