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Consolidated Statement of Stockholders' Equity (Parenthetical) - USD ($) | 12 Months Ended
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Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Statement of Stockholders' Equity [Abstract] |  |  |
Tax effect of change in post retirement benefits | $ 255,000 | $ 12,000 | $ 81,000
Tax effect of change in interest rate swaps |  | 2,000 | $ 8,000
Tax effect of change in Foreign Currency Translation Adjustment | $ 2,000 | $ 103,000 |

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