| **Long-Term Debt And Lease Obligation (Long-Term Debt and Lease Obligation Narrative) (Details) - USD ($) $ in Millions** | 12 Months Ended |        |
|---------------------------------------------------------------------------------------------------------------------------|-----------------|--------|
||
| **Lessee, Lease, Description [Line Items]**                                                                               |            |   |
| Total lease liability                                                                                                     | $ 59            | $ 52   |
| Lessee, Operating Lease, Term of Contract                                                                                 | 5 years         |   |
| Total lease liability                                                                                                     | $ 59            | $ 52   |
| Interest Costs Incurred                                                                                                   | $ 6             |   |
| Maximum                                                                                                                   |            |   |
| **Lessee, Lease, Description [Line Items]**                                                                               |            |   |
| Lessee, Finance Lease, Term of Contract                                                                                   | 6 years         |   |
| Minimum [Member]                                                                                                          |            |   |
| **Lessee, Lease, Description [Line Items]**                                                                               |            |   |
| Lessee, Finance Lease, Term of Contract                                                                                   | 3 years         |   |

| X                                                                                                                                                                                                                               |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Total lease liability
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Total interest costs incurred during the period and either capitalized or charged against earnings.
+ References
Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 835 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483013/835-20-50-1
+ Details**Name:**us-gaap_InterestCostsIncurred**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Term of lessee's finance lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.
+ References
Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 842 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (a)(3) -Publisher FASB -URI https://asc.fasb.org//1943274/2147478964/842-20-50-3
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.
+ References
Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 842 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org//1943274/2147478964/842-20-50-3
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Term of lessee's operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.
+ References
Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 842 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (a)(3) -Publisher FASB -URI https://asc.fasb.org//1943274/2147478964/842-20-50-3
+ Details**Name:**us-gaap_LesseeOperatingLeaseTermOfContract**Namespace Prefix:**us-gaap_**Data Type:**xbrli:durationItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                       |
|-------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**srt_RangeAxis=srt_MaximumMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                       |
|-------------------------------------------------------------------------------------------------------------------------|
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