PENSION PLANS - Financial information relating to pension plan (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
CHANGE IN BENEFIT OBLIGATION:
Net benefit obligation - beginning of period	$ 14,224	$ 13,933
Interest cost	665	658	$ 644
Actuarial loss	344	408
Gross benefits paid	(925)	(775)
Net benefit obligation - end of period	14,308	14,224	13,933
CHANGE IN PLAN ASSETS:
Fair value of plan assets - beginning of period	14,568	13,009
Employer contributions	400	400
Gross benefits paid	(925)	(775)
Return on plan assets	1,897	1,934
Fair value of plan assets - end of period	15,940	14,568	$ 13,009
Over funded status at end of period	$ 1,632	$ 344