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Stockholders' Equity (Tables) | 12 Months Ended
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Dec. 31, 2017
Stockholders' Equity Attributable to Parent [Abstract] |
Summary Of Common Stock Activity [Table Text Block] | The following table summarizes Common Stock activity from April 2, 2017 to December 31, 2017:
| Successor
| April 2 through December 31, 2017
| (In millions)
Shares outstanding at the beginning of the period | 70.9 |
Shares issued for preferred share conversions | 33.8 |
Shares issued for warrant conversions | 6.2 |
Shares issued for vested restricted stock units | 0.1 |
Shares repurchased | (5.8 | )
Shares outstanding at the end of the period | 105.2 |
Summary of Preferred Stock Activity [Table Text Block] | The following table summarizes the Series A Convertible Preferred Stock activity from April 2, 2017 to December 31, 2017:
| Successor
| April 2 through December 31, 2017
| (In millions)
Shares outstanding at the beginning of the period | 30.0 |
Shares converted to Common Stock | (17.2 | )
Shares issued for payable in-kind preferred stock dividends | 0.7 |
Shares outstanding at the end of the period | 13.5 |

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