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Investments (Tables) | 12 Months Ended
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Dec. 31, 2018
Investments [Abstract] |
Investments schedule [Table Text Block] |
| As of December 31,
(in thousands) | 2018 |  | 2017
Rabbi trust (associated with the Non-Qualified Deferred Compensation Plan) | $ | 6,689 |  |  | $ | 6,734 |
Investments in equity securities | 22 |  |  | 22 |
Total | $ | 6,711 |  |  | $ | 6,756 |

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- Definition [Table Text Block] for Investments schedule [Table] + References No definition available. + Details
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- References No definition available. + Details
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