ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Details 2) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Tax expense (benefit)	$ (10,678)	$ (8,982)	$ (21,100)	$ (19,118)
Net of tax			38,573
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Prior service credits	(280)	(72)	(560)	(144)
Actuarial losses	61	2,258	122	4,516
Total before tax	(219)	2,186	(438)	4,372
Tax expense (benefit)	83	(804)	166	(1,608)
Net of tax	$ (136)	$ 1,382	$ (272)	$ 2,764