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Earnings Per Share (Tables) | 12 Months Ended
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Dec. 31, 2018
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Schedule Of Basic And Diluted Earnings Per Share |
|  |  | Years Ended December 31, |
In millions except per share amounts |  | 2018 |  | 2017 |  |  | 2016 |
Basic earnings per share: |  |  |  |  |  |  |  |  |  |
| Net income (loss) available to common shareholders |  |  | (296) |  |  | (1,605) |  |  | (338) |
| Basic weighted average shares (1) |  |  | 89.0 |  |  | 118.9 |  |  | 133.0 |
| Net income (loss) per basic common share |  | $ | (3.33) |  | $ | (13.50) |  | $ | (2.54) |
Diluted earnings per share: |  |  |  |  |  |  |  |  |  |
| Net income (loss) available to common shareholders |  |  | (296) |  |  | (1,605) |  |  | (338) |
| Diluted weighted average shares |  |  | 89.0 |  |  | 118.9 |  |  | 133.0 |
| Net income (loss) per diluted common share |  | $ | (3.33) |  | $ | (13.50) |  | $ | (2.54) |
| Potentially dilutive securities excluded from the diluted EPS because of antidilutive affect |  |  | 4.4 |  |  | 14.1 |  |  | 16.5 |
| (1) Includes 0.8 million, 0.3 million and 0.9 million of participating securities that met the service condition and were eligible to receive nonforfeitable dividends or dividend |
| equivalents for the years ended December 31, 2018, 2017 and 2016, respectively. |

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