EMPLOYEE BENEFIT PLANS - Included in AOCI (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Supplemental Benefit Plan
Pre-tax amounts included in accumulated other comprehensive loss that have not yet been recognized in net periodic benefit cost
Unrecognized net actuarial (gain) loss	$ 64	$ 127
Total	64	127
Postretirement Health Benefit Plan
Pre-tax amounts included in accumulated other comprehensive loss that have not yet been recognized in net periodic benefit cost
Unrecognized net actuarial (gain) loss	(4,454)	(3,024)
Unrecognized prior service credit		(1)
Total	$ (4,454)	$ (3,025)

Amount, before tax, of accumulated other comprehensive (income) loss for defined benefit plan, that has not been recognized in net periodic benefit cost (credit).

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- Definition

Amount, before tax, of accumulated other comprehensive income (loss) for gain (loss) of defined benefit plan, that has not been recognized in net periodic benefit (cost) credit.

+ References

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-Publisher FASB
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- Definition

Amount, before tax, of accumulated other comprehensive (income) loss for cost (credit) of benefit change attributable to participants' prior service from plan amendment or plan initiation of defined benefit plan, that has not been recognized in net periodic benefit cost (credit).

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