| **Net Income Per Common Share (Tables)**              | 6 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
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| **Earnings Per Share [Abstract]**                     |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| Calculations For Basic And Diluted Earnings Per Share | The table shows calculations for basic and diluted earnings per share:(In millions except per share data) Three months ended June 30, Six months ended June 30, 2014 2013 2014 2013Numerator:        Net income—basic and diluted $84 $110 $175 $264Denominator:        Basic weighted-average common shares outstanding 163.5 163.5 163.5 163.3Effect of stock-based awards:        Stock options 1.0 1.2 1.0 1.1Nonvested shares 0.6 0.7 0.6 0.7Adjusted diluted weighted-average shares  165.1 165.4 165.1 165.2Earnings per share:        Basic $0.51 $0.67 $1.07 $1.62Diluted 0.51 0.66 1.06 1.60Number of anti-dilutive share-based awards 0.7 0.3 0.7 0.4          |

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| - Definition
Tabular disclosure of an entity's basic and diluted earnings per share calculations, including a reconciliation of numerators and denominators of the basic and diluted per-share computations for income from continuing operations.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257
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