| Dilutive Effect on Earnings Per Share | The following tables illustrate the dilutive effect of such items on earnings per share for the three and nine months ended September 30, 2018 and 2017: 
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|  | Three Months Ended September 30, 2018 |  |  |  |  |  |  |  |  |  |  |  |  |  
|  |  |  | Income (Loss) |  |  |  | Income (Loss) |  |  |  |  |  |  |  
|  |  |  | From Continuing Operations
 |  |  |  | From Discontinued Operations
 |  |  |  | Net Income (Loss)
 |  |  |  
|  | Weighted Average
 Shares
 |  | Amount |  | Per Share
 Amount
 |  | Amount |  | Per Share
 Amount
 |  | Amount |  | Per Share
 Amount
 |  
|  | (In thousands, except per share amounts) |  |  |  |  |  |  |  |  |  |  |  |  |  
| Earnings (loss) and shares | 42,673 |  | $ | 15,301 |  |  |  | $ | (183) |  |  |  | $ | 15,118 |  |  |  
| Effect of participating securities: |  |  |  |  |  |  |  |  |  |  |  |  |  |  
| Non-vested restricted stock |  |  | (14) |  |  |  | — |  |  |  | (14) |  |  |  
| Basic earnings (loss) and shares | 42,673 |  | $ | 15,287 |  | $ | 0.36 |  | $ | (183) |  | $ | (0.01) |  | $ | 15,104 |  | $ | 0.35 |  
| Effect of dilutive securities: |  |  |  |  |  |  |  |  |  |  |  |  |  |  
| Stock compensation plans | 321 |  |  |  |  |  |  |  |  |  |  |  |  |  
| Diluted earnings (loss) and shares | 42,994 |  | $ | 15,287 |  | $ | 0.36 |  | $ | (183) |  | $ | (0.01) |  | $ | 15,104 |  | $ | 0.35 | 
 
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
|  | Three Months Ended September 30, 2017 |  |  |  |  |  |  |  |  |  |  |  |  |  
|  |  |  | Income (Loss) |  |  |  | Income (Loss) |  |  |  |  |  |  |  
|  |  |  | From Continuing Operations
 |  |  |  | From Discontinued Operations
 |  |  |  | Net Income (Loss)
 |  |  |  
|  | Weighted Average
 Shares
 |  | Amount |  | Per Share
 Amount
 |  | Amount |  | Per Share
 Amount
 |  | Amount |  | Per Share
 Amount
 |  
|  | (In thousands, except per share amounts) |  |  |  |  |  |  |  |  |  |  |  |  |  
| Earnings (loss) and shares | 43,496 |  | $ | 19,730 |  |  |  | $ | (290) |  |  |  | $ | 19,440 |  |  |  
| Effect of participating securities: |  |  |  |  |  |  |  |  |  |  |  |  |  |  
| Non-vested restricted stock |  |  | (18) |  |  |  | — |  |  |  | (18) |  |  |  
| Basic earnings (loss) and shares | 43,496 |  | $ | 19,712 |  | $ | 0.45 |  | $ | (290) |  | $ | — |  | $ | 19,422 |  | $ | 0.45 |  
| Effect of dilutive securities: |  |  |  |  |  |  |  |  |  |  |  |  |  |  
| Stock compensation plans | 315 |  |  |  |  |  |  |  |  |  |  |  |  |  
| Diluted earnings (loss) and shares | 43,811 |  | $ | 19,712 |  | $ | 0.45 |  | $ | (290) |  | $ | (0.01) |  | $ | 19,422 |  | $ | 0.44 | 
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
|  | Nine Months Ended September 30, 2018 |  |  |  |  |  |  |  |  |  |  |  |  |  
|  |  |  | Income (Loss) |  |  |  | Income (Loss) |  |  |  |  |  |  |  
|  |  |  | From Continuing Operations
 |  |  |  | From Discontinued Operations
 |  |  |  | Net Income (Loss)
 |  |  |  
|  | Weighted Average
 Shares
 |  | Amount |  | Per Share
 Amount
 |  | Amount |  | Per Share
 Amount
 |  | Amount |  | Per Share
 Amount
 |  
|  | (In thousands, except per share amounts) |  |  |  |  |  |  |  |  |  |  |  |  |  
| Earnings (loss) and shares | 42,708 |  | $ | 30,409 |  |  |  | $ | (579) |  |  |  | $ | 29,830 |  |  |  
| Effect of participating securities: |  |  |  |  |  |  |  |  |  |  |  |  |  |  
| Non-vested restricted stock |  |  | (29) |  |  |  | — |  |  |  | (29) |  |  |  
| Basic earnings (loss) and shares | 42,708 |  | $ | 30,380 |  | $ | 0.71 |  | $ | (579) |  | $ | (0.01) |  | $ | 29,801 |  | $ | 0.70 |  
| Effect of dilutive securities: |  |  |  |  |  |  |  |  |  |  |  |  |  |  
| Stock compensation plans | 256 |  |  |  |  |  |  |  |  |  |  |  |  |  
| Diluted earnings (loss) and shares | 42,964 |  | $ | 30,380 |  | $ | 0.71 |  | $ | (579) |  | $ | (0.02) |  | $ | 29,801 |  | $ | 0.69 | 
 
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
|  | Nine Months Ended September 30, 2017 |  |  |  |  |  |  |  |  |  |  |  |  |  
|  |  |  | Income (Loss) |  |  |  | Income (Loss) |  |  |  |  |  |  |  
|  |  |  | From Continuing Operations
 |  |  |  | From Discontinued Operations
 |  |  |  | Net Income (Loss)
 |  |  |  
|  | Weighted Average
 Shares
 |  | Amount |  | Per Share
 Amount
 |  | Amount |  | Per Share
 Amount
 |  | Amount |  | Per Share
 Amount
 |  
|  | (In thousands, except per share amounts) |  |  |  |  |  |  |  |  |  |  |  |  |  
| Earnings (loss) and shares | 44,281 |  | $ | 32,024 |  |  |  | $ | (993) |  |  |  | $ | 31,031 |  |  |  
| Effect of participating securities: |  |  |  |  |  |  |  |  |  |  |  |  |  |  
| Non-vested restricted stock |  |  | (28) |  |  |  | — |  |  |  | (28) |  |  |  
| Basic earnings (loss) and shares | 44,281 |  | $ | 31,996 |  | $ | 0.72 |  | $ | (993) |  | $ | (0.02) |  | $ | 31,003 |  | $ | 0.70 |  
| Effect of dilutive securities: |  |  |  |  |  |  |  |  |  |  |  |  |  |  
| Stock compensation plans | 304 |  |  |  |  |  |  |  |  |  |  |  |  |  
| Diluted earnings (loss) and shares | 44,585 |  | $ | 31,996 |  | $ | 0.72 |  | $ | (993) |  | $ | (0.02) |  | $ | 31,003 |  | $ | 0.70 |  |