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Dividends (Tables) | 12 Months Ended
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Dec. 31, 2017
Dividends [Abstract] |
Dividends Paid In Total And Per Share | The following table presents shareholder dividends paid:
| Year Ended December 31,
| 2017 |  | 2016 |  | 2015
| (Amounts in thousands, except per share data)
Total paid | $ | 137,886 |  |  | $ | 137,201 |  |  | $ | 136,386 |
Per share paid | $ | 2.4925 |  |  | $ | 2.4825 |  |  | $ | 2.4725 |

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