COMPONENTS OF QUARTERLY AND YEAR TO DATE NET PERIODIC BENEFIT COSTS (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Qualified Pension Plan
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost, benefits earned during the period	$ 0	$ 0
Interest cost on projected benefit obligation	379	385
Expected return on plan assets	(554)	(826)
Amortization of unrecognized transition obligation	0	0
Amortization of unrecognized prior service cost	0	0
Amortization of unrecognized net loss	49	43
Net periodic pension benefit	(126)	(398)
Supplemental Pension Plan
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost, benefits earned during the period	0	0
Interest cost on projected benefit obligation	13	12
Expected return on plan assets	0	0
Amortization of unrecognized prior service cost	0	0
Amortization of unrecognized net loss	1	2
Net periodic pension benefit	14	14
Postretirement Plan, Medical and Life
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost, benefits earned during the period	0	0
Interest cost on projected benefit obligation	3	3
Expected return on plan assets	0	0
Amortization of unrecognized prior service cost	(55)	(55)
Amortization of unrecognized net loss	23	28
Net periodic pension benefit	$ (29)	$ (24)