RETIREMENT PLANS, NET PERIODIC BENEFIT COSTS (Details) - Qualified noncontributory defined benefit retirement plan - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	$ 0	$ 41	$ 38
Interest cost	69	78	68
Amortization of unrecognized (gain) loss	16	168	171
Net periodic pension cost	$ 85	$ 287	$ 277