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Earnings Per Share (Tables) | 6 Months Ended
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Jun. 30, 2021
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Schedule Of Basic And Diluted Earnings Per Share | The following table presents the computation of basic and diluted earnings per share for the three and six months ended June 30, 2021 and 2020:
|  | Three Months Ended June 30, |  | Six Months Ended June 30,
In millions except per share amounts |  | 2021 |  | 2020 |  | 2021 |  | 2020
Basic earnings per share: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net income (loss) |  | $ | (61 | ) |  | $ | (106 | ) |  | $ | (167 | ) |  | $ | (439 | )
Less: undistributed earnings allocated to participating securities |  |  | - |  |  |  | - |  |  |  | - |  |  |  | - |
Net income (loss) available to common shareholders |  | $ | (61 | ) |  | $ | (106 | ) |  | $ | (167 | ) |  | $ | (439 | )
Basic weighted average shares (1) |  |  | 49.5 |  |  |  | 62.6 |  |  |  | 49.4 |  |  |  | 67.3 |
Net income (loss) per basic common share |  | $ | (1.23 | ) |  | $ | (1.69 | ) |  | $ | (3.38 | ) |  | $ | (6.51 | )
Diluted earnings per share: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net income (loss) |  | $ | (61 | ) |  | $ | (106 | ) |  | $ | (167 | ) |  | $ | (439 | )
Less: undistributed earnings allocated to participating securities |  |  | - |  |  |  | - |  |  |  | - |  |  |  | - |
Net income (loss) available to common shareholders |  | $ | (61 | ) |  | $ | (106 | ) |  | $ | (167 | ) |  | $ | (439 | )
Diluted weighted average shares |  |  | 49.5 |  |  |  | 62.6 |  |  |  | 49.4 |  |  |  | 67.3 |
Net income (loss) per diluted common share |  | $ | (1.23 | ) |  | $ | (1.69 | ) |  | $ | (3.38 | ) |  | $ | (6.51 | )
Potentially dilutive securities excluded from the calculation of diluted EPS because of antidilutive affect |  |  | 4.9 |  |  |  | 4.9 |  |  |  | 4.9 |  |  |  | 4.9 |
(1) - | Includes 0.9 million of participating securities that met the service condition and were eligible to receive nonforfeitable dividends or dividend equivalents for each of the three months and six months ended June 30, 2021 and 2020 .

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