PENSION AND OTHER POSTRETIREMENT PLANS - Amounts Recognized in AOCI (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Amounts recognized in accumulated other comprehensive income
Net amount recognized	$ 6,365	$ 5,533
Pension Benefits
Amounts recognized in accumulated other comprehensive income
Net actuarial loss	8,631	6,987
Prior service cost	(561)	(639)
Transition obligation	0	0
Net amount recognized	8,070	6,348
SERP Benefits
Amounts recognized in accumulated other comprehensive income
Net actuarial loss	925	1,459
Prior service cost	0	0
Transition obligation	0	5
Net amount recognized	$ 925	$ 1,464

Amount, after 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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Amount, after 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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- Definition

Amount, after 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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- Definition

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

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