| **Employee Retirement Benefits (Reconciliation Of The Funded Status For Qualified Plan And SERP) (Details) - USD ($) $ in Millions** | Dec. 31, 2016 | Dec. 31, 2015 |
|--------------------------------------------------------------------------------------------------------------------------------------|---------------|---------------|
| **Compensation and Retirement Disclosure [Abstract]**                                                                                |          |          |
| Other liabilities                                                                                                                    | $ (25)        | $ (45)        |
| Total                                                                                                                                | (25)          | (45)          |
| **Pension amounts recognized in accumulated other comprehensive income:**                                                            |          |          |
| Net actuarial loss                                                                                                                   | 26            | 41            |
| Prior service cost                                                                                                                   | 0             | 1             |
| Total                                                                                                                                | $ 26          | $ 42          |

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| - References
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| - Definition
The pretax total of net gain (loss), prior service cost (credit), and transition assets (obligations), as well as minimum pension liability if still remaining, included in accumulated other comprehensive income associated with a defined benefit pension or other postretirement plan(s) because they have yet to be recognized as components of net periodic benefit cost.
+ References
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| - Definition
The pretax net amount of gains and losses that are not yet recognized as a component of net periodic benefit cost, and that are recognized as increases or decreases in other comprehensive income as they arise. Gains and losses are due to changes in the value of either the benefit obligation or the plan assets resulting from experience different from that assumed or from a change in an actuarial assumption, or the consequence of a decision to temporarily deviate from the substantive plan.
+ References
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| - Definition
Amount related to the pretax cost of benefit changes attributable to plan participants' prior service pursuant to a plan amendment or a plan initiation, which has not yet been recognized as components of net periodic benefit cost.
+ References
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| - Definition
The aggregate net amount recognized in the balance sheet associated with the defined benefit plan(s). Will normally be the same as the Defined Benefit Plan, Funded Status of Plan, Total.
+ References
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| - Definition
This represents the entire liability recognized in the balance sheet that is associated with the defined benefit plans.
+ References
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