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, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Components of Net Periodic Benefit Cost
Service cost	$ 1,249	$ 1,429	$ 2,498	$ 2,858
Interest cost	9,410	8,875	18,820	17,751
Expected return on plan assets	(11,937)	(14,797)	(23,875)	(29,594)
Amortization of prior service cost	335	335	670	670
Amortization of actuarial loss	1,358	2,456	2,716	4,913
Net periodic benefit cost (credit)	415	(1,702)	829	(3,402)
Pretax reclassification from AOCI included in net periodic pension benefit cost	$ 1,693	$ 2,791	$ 3,386	$ 5,583