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OTHER ASSETS (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items] |  |  |
Cash surrender value of the COLI | $ 12,300 | $ 10,900 |
Increase (decrease) in cash surrender value | 1,300 | 500 | $ (100)
Proceeds from sale of marketable securities | 0 | 2,164 | 2,820
Investments held in Rabbi Trust [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Cost of investments | 1,300 | 1,000 |
Fair value of investments | 1,500 | 1,700 |
Unrealized gain on investments | 200 | 700 |
Proceeds from sale of marketable securities |  | 2,200 |
Supplemental Employee Retirement Plans [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Benefit obligation | 19,134 | 16,900 | $ 15,576
Value of assets earmarked for SERP use but not restricted to that use | $ 14,000 | 12,700 |
Proceeds from sale of marketable securities |  | $ 2,200 |

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