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EMPLOYEE BENEFIT PLANS (Defined Contribution Plans) (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Cash Long-Term Incentive Compensation Plan |  |  |
Earning period of Long-term cash incentive plan | 3 years |  |
Incentive payments accrued for Long-Term Cash Incentive Plan | $ 6.6 | $ 3.9 | $ 6.7
Other Plans |  |  |
Cash surrender value of life insurance policies | 49.7 | 47.4 |
Recognized gains associated with changes in the cash surrender value and proceeds from life insurance policies | $ 2.6 | 2.9 | 0.3
401(k) Plan |  |  |
Defined Contribution Plans |  |  |
Maximum percentage of salary permitted to be deferred by plan participants | 69.00% |  |
Rate of employer match on participant contributions | 50.00% |  |
Maximum percentage of participants compensation that is eligible for 50% matching contribution | 6.00% |  |
Expense for employer contribution to defined contribution plan | $ 5.6 | 5.7 | 5.5
DC Retirement Plan |  |  |
Defined Contribution Plans |  |  |
Expense for employer contribution to defined contribution plan | $ 8.3 | $ 5.0 | $ 9.5
Period of service for participants' full vesting in the employer's contributions | 3 years |  |

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- Definition Amounts that were accrued at the end of the period under the Long-Term Cash Incentive Plan for payment in future periods. + References No definition available. + Details
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- Definition The minimum period that the individual is required to perform services in order to be fully vested under the deferred compensation arrangement. + References No definition available. + Details
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- Definition Represents the recognized gains associated with changes in the cash surrender value and proceeds from life insurance policies. + References No definition available. + Details
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- References No definition available. + Details
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- Definition Represents the earning period of incentives under the Long-Term Cash Incentive Plan. + References No definition available. + Details
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- Definition -- None. No documentation exists for this element. -- + References No definition available. + Details
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- Definition Carrying amount as of the balance sheet date of amounts which could be received based on the terms of the insurance contract upon surrendering life policies owned by the entity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.17) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section 45 -Paragraph 4 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=82887183&loc=d3e6812-107765 + Details
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- Definition Amount of cost for defined contribution plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 70 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942 + Details
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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- Definition Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan. + References No definition available. + Details
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- Definition Percentage employer matches of the employee's percentage contribution matched. + References No definition available. + Details
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- Definition Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan. + References No definition available. + Details
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- Details
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