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EMPLOYEE BENEFIT PLANS (Nonunion Plan Assets - FV) (Details) - Nonunion Defined Benefit Pension Plan - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Pension and other postretirement benefit plans
Fair value of plan assets	$ 26,646	$ 124,831	$ 144,805
Cash and Cash Equivalents
Pension and other postretirement benefit plans
Fair value of plan assets	19,856	16,641
Debt Instruments
Pension and other postretirement benefit plans
Fair value of plan assets	10	91,778
Floating Rate Loan Fund
Pension and other postretirement benefit plans
Fair value of plan assets	6,780	16,412
Level 1
Pension and other postretirement benefit plans
Fair value of plan assets	26,636	43,140
Level 1 | Cash and Cash Equivalents
Pension and other postretirement benefit plans
Fair value of plan assets	19,856	16,641
Level 1 | Debt Instruments
Pension and other postretirement benefit plans
Fair value of plan assets		10,087
Level 1 | Floating Rate Loan Fund
Pension and other postretirement benefit plans
Fair value of plan assets	6,780	16,412
Level 2
Pension and other postretirement benefit plans
Fair value of plan assets	10	81,691
Level 2 | Debt Instruments
Pension and other postretirement benefit plans
Fair value of plan assets	$ 10	$ 81,691
Level 2 | Corporate debt securities
Pension and other postretirement benefit plans
Percentage of investments in debt instruments		80.00%
Level 2 | Asset-backed securities
Pension and other postretirement benefit plans
Percentage of investments in debt instruments		16.00%
Level 2 | Mortgage-backed instruments
Pension and other postretirement benefit plans
Percentage of investments in debt instruments		4.00%

X

- Definition

Represents the percentage of the entity's defined benefit pension plan investments in debt instruments that belong to a particular class or type of security.

+ References

No definition available.

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- Definition

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+ References

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- Definition

Amount of asset segregated and restricted to provide benefit under defined benefit plan. Asset includes, but is not limited to, stock, bond, other investment, earning from investment, and contribution by employer and employee.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(iv)(01)
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