BENEFIT PLANS (Components of Net Periodic Benefit Cost- Pension Benefits) (Details) - Pension Benefits [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Components of Net Periodic Benefit Cost
Service cost	$ 1,653	$ 1,335	$ 4,961	$ 4,007
Interest cost	9,057	9,127	27,172	27,379
Expected return on plan assets	(12,097)	(12,891)	(36,289)	(38,672)
Amortization of prior service cost (credit)	335	(11)	1,005	(32)
Amortization of actuarial (gain) loss	1,824	1,540	5,471	4,622
Net periodic benefit cost (credit)	772	(900)	2,320	(2,696)
Pretax reclassification from AOCI included in net periodic pension/postretirement benefit cost (credit)	$ 2,159	$ 1,529	$ 6,476	$ 4,590