PENSION AND OTHER POSTRETIREMENT PLANS (Amounts Recognized in Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure
Net actuarial loss	$ (110)	$ 153	$ (372)
Pension Benefits
Defined Benefit Plan Disclosure
Net actuarial loss	1,362	1,464
SERP Benefits
Defined Benefit Plan Disclosure
Net actuarial loss	$ 553	$ 597

Amount, after tax and reclassification adjustment, of (increase) decrease in accumulated other comprehensive income for defined benefit plan, attributable to parent.

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