BENEFIT PLANS (Components of Net Periodic Benefit Cost- Pension Benefits) (Details) - Pension Benefits [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Components of Net Periodic Benefit Cost
Service cost	$ 1,249	$ 1,429
Interest cost	9,410	8,876
Expected return on plan assets	(11,938)	(14,797)
Amortization of prior service cost	335	335
Amortization of actuarial loss	1,358	2,457
Net periodic benefit cost (credit)	414	(1,700)
Pretax reclassification from AOCI included in net periodic pension benefit cost	$ 1,693	$ 2,792