COMPONENTS OF QUARTERLY AND YEAR TO DATE NET PERIODIC BENEFIT COSTS (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Qualified Pension Plan [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost, benefits earned during the period	$ 298	$ 354	$ 892	$ 1,061
Interest cost on projected benefit obligation	470	457	1,410	1,371
Expected return on plan assets	(756)	(824)	(2,267)	(2,471)
Amortization of unrecognized transition obligation	0	0	0	0
Amortization of unrecognized prior service cost	1	2	5	7
Amortization of unrecognized net loss	383	369	1,150	1,106
Net periodic pension cost	396	358	1,190	1,074
Supplemental Pension Plan [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost, benefits earned during the period	11	11	32	33
Interest cost on projected benefit obligation	13	13	39	37
Expected return on plan assets	0	0	0	0
Amortization of unrecognized prior service cost	0	0	0	0
Amortization of unrecognized net loss	6	12	19	38
Net periodic pension cost	30	36	90	108
Postretirement Plan, Medical and Life
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost, benefits earned during the period	11	11	35	35
Interest cost on projected benefit obligation	18	16	53	48
Expected return on plan assets	0	0	0	0
Amortization of unrecognized prior service cost	(23)	(24)	(72)	(72)
Amortization of unrecognized net loss	7	3	19	7
Net periodic pension cost	$ 13	$ 6	$ 35	$ 18