BENEFIT PLANS (Components of Net Periodic Benefit Cost, Amounts Recognized in Other Comprehensive Income, Weighted-Average Assumptions) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Pension Plans, Defined Benefit [Member]
Components of Net Periodic Benefit Cost
Service cost	$ 1,213	$ 1,039
Interest cost	11,037	11,098
Expected return on plan assets	(13,684)	(12,701)
Amortization of prior service cost (credit)	12	47
Amortization of actuarial loss	5,454	2,805
Net periodic pension benefit cost	4,032	2,288
Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income
Pretax reclassification from AOCI included in net periodic postretirement benefit cost	5,466	2,852
Other Postretirement Benefit Plans, Defined Benefit [Member]
Components of Net Periodic Benefit Cost
Service cost	473	536
Interest cost	617	824
Curtailment gain	0	(3,832)
Amortization of prior service cost (credit)	(1,058)	(1,082)
Amortization of actuarial loss	(4)	57
Net periodic pension benefit cost	28	(3,497)
Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income
Pretax reclassification from AOCI included in net periodic postretirement benefit cost	$ (1,062)	$ (4,857)