| **Long-Term Debt And Capital Lease Obligation (Book Value And Principal Amounts Of Long-Term Debt (Details) - USD ($) $ in Millions** | 12 Months Ended |        |
|---------------------------------------------------------------------------------------------------------------------------------------|-----------------|--------|
||
| **Debt Instrument**                                                                                                                   |            |   |
| Book value                                                                                                                            | $ 786           | $ 786  |
| Principal amount                                                                                                                      | $ 793           | $ 793  |
| 6.900% Senior Debentures, Due 2028                                                                                                    |            |   |
| **Debt Instrument**                                                                                                                   |            |   |
| Interest rate                                                                                                                         | 6.90%           | 6.90%  |
| Debt issuance year                                                                                                                    | 1998            |   |
| Book value                                                                                                                            | $ 26            | $ 26   |
| Principal amount                                                                                                                      | $ 28            | $ 28   |
| 6.920% Senior Debentures, Due 2028                                                                                                    |            |   |
| **Debt Instrument**                                                                                                                   |            |   |
| Interest rate                                                                                                                         | 6.92%           | 6.92%  |
| Debt issuance year                                                                                                                    | 2005            |   |
| Book value                                                                                                                            | $ 391           | $ 391  |
| Principal amount                                                                                                                      | $ 391           | $ 391  |
| 6.125% Senior Notes, Due 2034                                                                                                         |            |   |
| **Debt Instrument**                                                                                                                   |            |   |
| Interest rate                                                                                                                         | 6.125%          | 6.125% |
| Debt issuance year                                                                                                                    | 2004            |   |
| Book value                                                                                                                            | $ 369           | $ 369  |
| Principal amount                                                                                                                      | $ 374           | $ 374  |

| X                                                                                                                                                                                                                                          |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Debt instrument issuance year.
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Face (par) amount of debt instrument at time of issuance.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Contractual interest rate for funds borrowed, under the debt agreement.
+ References
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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
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.
+ References
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| X                                                                                                                                                              |
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| X                                                                                                                                                               |
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| X                                                                                                                                                           |
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