COMMITMENTS AND CONTINGENCIES (Other Contingencies) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Product Liability Contingency [Line Items]
Retention for environmental impairment	$ 1,000
Self-insurance liabilities	$ 47,900	$ 46,500
Weighted average risk free discount rate for self insurance liabilities	1.87%	1.16%
Self Insurance Losses Expected [Abstract]
2018	$ 16,525
2019	11,259
2020	7,848
2021	4,393
2022	3,688
Thereafter	5,769
Undiscounted self-insurance liabilities	49,482
Less: Discount	1,568
Total self-insurance liabilities (included in accrued expenses)	47,914
Minimum
Product Liability Contingency [Line Items]
Deductible health insurance policy	700
Safety-Kleen
Product Liability Contingency [Line Items]
Deductible per occurrence for workers compensation	1,000
Deductible per occurrence for general liability	2,000
Deductible per occurrence for vehicle liability	$ 2,000