BENEFIT PLANS (Components of Net Periodic Benefit Cost- Pension Benefits) (Details) - Pension 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	$ 1,654	$ 1,336	$ 3,308	$ 2,672
Interest cost	9,058	9,126	18,115	18,252
Expected return on plan assets	(12,096)	(12,890)	(24,192)	(25,781)
Amortization of prior service cost (credit)	335	(10)	670	(21)
Amortization of actuarial (gain) loss	1,823	1,541	3,647	3,082
Net periodic benefit cost (credit)	774	(897)	1,548	(1,796)
Pretax reclassification from AOCI included in net periodic pension/postretirement benefit cost (credit)	$ 2,158	$ 1,531	$ 4,317	$ 3,061