ACCUMULATED OTHER COMPREHENSIVE LOSS (Income Tax Expense Allocated to Each Component of Other Comprehensive Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Tax provision	$ 677	$ 297	$ 223
Unrealized losses on cash flow hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Current period change excluding amounts reclassified from accumulated other comprehensive loss	0	30	553
Tax provision	(513)	(118)	0
Total change in accumulated other comprehensive loss	(513)	(88)	553
Items not yet recognized as a component of net periodic benefit cost (pension and other postretirement plans)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Current period change excluding amounts reclassified from accumulated other comprehensive loss	(203)	(388)	(353)
Tax provision	(164)	(179)	(223)
Total change in accumulated other comprehensive loss	$ (367)	$ (567)	$ (576)