RETIREMENT PLANS, NET PERIODIC BENEFIT COSTS (Details) - Qualified noncontributory defined benefit retirement plan - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	$ 0	$ 0	$ 0
Interest cost	63	77	69
Amortization of unrecognized (gain) loss	2	0	16
Net periodic pension cost	$ 65	$ 77	$ 85