BENEFIT PLANS (Components of Net Periodic Benefit Cost- Other Postretirement Benefits) (Details) - Other Postretirement Benefits [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Components of Net Periodic Benefit Cost
Service cost	$ 291	$ 280	$ 583	$ 561
Interest cost	315	303	630	605
Amortization of prior service cost (credit)	(1,059)	(1,059)	(2,118)	(2,118)
Amortization of actuarial (gain) loss	(396)	(437)	(793)	(875)
Net periodic benefit cost (credit)	(849)	(913)	(1,698)	(1,827)
Pretax reclassification from AOCI included in net periodic pension/postretirement benefit cost (credit)	$ (1,455)	$ (1,496)	$ (2,911)	$ (2,993)