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Shareholders’ Equity (Tables) | 3 Months Ended
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Mar. 31, 2019
Stockholders' Equity Note [Abstract] |
Common and Preferred Stock Activity | The Common and Preferred Stock table below contains additional information about preferred stock conversions during the three months ended March 31, 2019 and 2018.
| Preferred stock |  | Common stock
Common and Preferred Stock Activity (in shares): | Series A convertible |  | Treasury |  | Outstanding
Beginning balance as of December 31, 2018 | 71,967 |  |  | 7,186,521 |  |  | 88,103,440 |
Conversion of convertible preferred stock | (3,023 | ) |  | — |  |  | 302,255 |
Issuance for share-based compensation plans | — |  |  | — |  |  | 402,062 |
Ending balance as of March 31, 2019 | 68,944 |  |  | 7,186,521 |  |  | 88,807,757 |
Beginning balance as of December 31, 2017 | 74,364 |  |  | 7,186,521 |  |  | 87,544,777 |
Conversion of convertible preferred stock | (133 | ) |  | — |  |  | 13,343 |
Issuance for share-based compensation plans | — |  |  | — |  |  | 17,749 |
Ending balance as of March 31, 2018 | 74,231 |  |  | 7,186,521 |  |  | 87,575,869 |

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- Definition Tabular disclosure of the change in preferred stock, treasury stock and common stock outstanding. + References No definition available. + Details
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