COMMITMENTS AND CONTINGENCIES (Other Contingencies) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Product Liability Contingency [Line Items]
Retention for environmental impairment	$ 1,000
Self-insurance liabilities	$ 53,900	$ 47,900
Weighted average risk free discount rate for self insurance liabilities	2.96%	1.87%
Self Insurance Losses Expected [Abstract]
2019	$ 20,171
2020	12,799
2021	7,964
2022	4,992
2023	4,082
Thereafter	6,385
Undiscounted self-insurance liabilities	56,393
Less: Discount	2,492
Total self-insurance liabilities (included in accrued expenses)	53,901
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