ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Reclassifications (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Tax (benefit) expense	$ (4,621)	$ (7,182)	$ (10,288)	$ (12,946)
Net of tax			3,631
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Prior service credits	(182)	(371)	(364)	(742)
Actuarial losses	348	155	696	310
Loss recognized during settlement	4,608	0	4,608	0
Total before tax	4,774	(216)	4,940	(432)
Tax (benefit) expense	(1,265)	78	(1,309)	157
Net of tax	$ 3,509	$ (138)	$ 3,631	$ (275)

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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