BENEFIT PLANS (Components of Net Periodic Benefit Cost) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1,335	$ 1,213	$ 4,007	$ 3,638
Interest cost	9,127	11,004	27,379	33,077
Expected return on plan assets	(12,891)	(13,683)	(38,672)	(41,051)
Settlement charge	0	2,031	0	2,031
Amortization of prior service cost (credit)	(11)	12	(32)	36
Amortization of actuarial (gain) loss	1,540	5,383	4,622	16,292
Net periodic benefit cost (credit)	(900)	5,960	(2,696)	14,023
Pretax reclassification from AOCI included in net periodic pension/postretirement benefit cost (credit)	1,529	7,426	4,590	18,359
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	281	473	842	1,420
Interest cost	302	621	907	1,864
Amortization of prior service cost (credit)	(1,059)	(1,058)	(3,177)	(3,174)
Amortization of actuarial (gain) loss	(438)	9	(1,313)	28
Net periodic benefit cost (credit)	(914)	45	(2,741)	138
Pretax reclassification from AOCI included in net periodic pension/postretirement benefit cost (credit)	$ (1,497)	$ (1,049)	$ (4,490)	$ (3,146)