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RETIREMENT PLANS - Net Assets and Allocations (Details) - Pension Plans - USD ($) $ in Thousands | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
--- | --- | --- | ---
Pension plan assets |  |  |
Fair value of plan assets | $ 80,892 | $ 75,331 | $ 11,946
Weighted-average asset allocations (as a percent) | 100.00% | 100.00% |
Level 1 |  |  |
Pension plan assets |  |  |
Fair value of plan assets | $ 41,827 | $ 62,053 |
Level 2 |  |  |
Pension plan assets |  |  |
Fair value of plan assets | 38,569 | 12,775 |
Level 3 |  |  |
Pension plan assets |  |  |
Fair value of plan assets | 496 | 503 |
Cash, cash equivalents, money markets and other |  |  |
Pension plan assets |  |  |
Fair value of plan assets | $ 6,363 | $ 32,976 |
Weighted-average asset allocations (as a percent) | 8.00% | 44.00% |
Cash, cash equivalents, money markets and other | Level 1 |  |  |
Pension plan assets |  |  |
Fair value of plan assets | $ 6,363 | $ 32,976 |
Common Stock |  |  |
Pension plan assets |  |  |
Fair value of plan assets | $ 28,467 | $ 22,560 |
Weighted-average asset allocations (as a percent) | 35.00% | 30.00% |
Common Stock | Level 1 |  |  |
Pension plan assets |  |  |
Fair value of plan assets | $ 25,312 | $ 21,344 |
Common Stock | Level 2 |  |  |
Pension plan assets |  |  |
Fair value of plan assets | 3,155 | 1,216 |
Mutual funds - equities |  |  |
Pension plan assets |  |  |
Fair value of plan assets | $ 9,248 | $ 7,141 |
Weighted-average asset allocations (as a percent) | 11.00% | 9.00% |
Mutual funds - equities | Level 1 |  |  |
Pension plan assets |  |  |
Fair value of plan assets | $ 9,248 | $ 6,180 |
Mutual funds - equities | Level 2 |  |  |
Pension plan assets |  |  |
Fair value of plan assets |  | 961 |
Exchange traded funds - equities |  |  |
Pension plan assets |  |  |
Fair value of plan assets | $ 904 | $ 1,553 |
Weighted-average asset allocations (as a percent) | 1.00% | 2.00% |
Exchange traded funds - equities | Level 1 |  |  |
Pension plan assets |  |  |
Fair value of plan assets | $ 904 | $ 1,553 |
Fixed income securities |  |  |
Pension plan assets |  |  |
Fair value of plan assets | $ 35,414 | $ 10,598 |
Weighted-average asset allocations (as a percent) | 44.00% | 14.00% |
Fixed income securities | Level 2 |  |  |
Pension plan assets |  |  |
Fair value of plan assets | $ 35,414 | $ 10,598 |
Annuities |  |  |
Pension plan assets |  |  |
Fair value of plan assets | $ 496 | $ 503 |
Weighted-average asset allocations (as a percent) | 1.00% | 1.00% |
Annuities | Level 3 |  |  |
Pension plan assets |  |  |
Fair value of plan assets | $ 496 | $ 503 |

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- Definition Fair value of assets that have been segregated and restricted to provide pension or postretirement benefits. Assets include, but are not limited to, stocks, bonds, other investments, earnings from investments, and contributions by the employer and employees. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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