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Stockholders' Equity (Tables) | 12 Months Ended
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Dec. 31, 2016
Stockholders' Equity (Tables) [Abstract] |
Summary of common stock activity | The following table summarizes common stock activity from January 1, 2014 to December 31, 2016:
| 2016 |  | 2015 |  | 2014
| (In millions)
Shares outstanding at the beginning of the year | 18.5 |  |  | 18.1 |  |  | 18.0 |
Stock grants to employees | — |  |  | 0.2 |  |  | 0.1 |
Performance share contribution 401k | — |  |  | 0.2 |  |  | — |
Shares outstanding at the end of the year | 18.5 |  |  | 18.5 |  |  | 18.1 |

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- Definition Summary of common stock activity. + References No definition available. + Details
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