| **Long-Term Debt And Capital Lease Obligation (Tables)**    | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
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| **Long-term Debt and Capital Lease Obligations [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
| Book Value And Principal Amounts Of Long-Term Debt          | This table summarizes the principal amounts of our long-term debt excluding unamortized discounts, none of which are encumbered by rating triggers:(Dollars in millions)   Book value Principal amount Interest rate  Year of issue   December 31, December 31, December 31, December 31,    2014 2013 2014 20136.900% 1998 Senior debentures, due 2028 $28 $28 $28 $286.920% 2005 Senior debentures, due 2028 391 391 391 3916.125% 2004 Senior notes, due 2034 372 371 374 374    Total $791 $790 $793 $793              |
| Capital Lease Payments Over Next Five Years                 | Below are the expected capital lease obligations that we expect to pay over the next six years:(Dollars in millions)Years ended December 31,  2015 2016 2017 2018 20192020Capital lease obligations$18 $9 $3 $2 $3$1                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |

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| - Definition
The entire disclosure for long-term debt.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5
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| - Definition
Tabular disclosure of future minimum lease payments as of the date of the latest balance sheet presented, in aggregate and for each of the five years succeeding fiscal years, with separate deductions from the total for the amount representing executor costs, including any profit thereon, included in the minimum lease payments and for the amount of the imputed interest necessary to reduce the net minimum lease payments to present value.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6455398&loc=d3e45280-112737
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