RETIREMENT PLANS, CHANGES IN PROJECTED BENEFIT OBLIGATION (Details) - Qualified noncontributory defined benefit retirement plan - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reconciliation of changes in projected benefit obligation [Abstract]
Projected benefit obligation at beginning of year	$ 1,727	$ 1,843	$ 1,741
Service cost	0	41	38
Interest cost	69	78	68
Actuarial (gain) or loss	238	(209)	10
Benefits paid	(63)	(26)	(14)
Projected benefit obligation at end of year	$ 1,971	$ 1,727	$ 1,843