OTHER ITEMS AND CHARGES (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Site Contingency [Line Items]
Expense from acquisition activities	$ 173	$ 1,097	$ 1,533	$ 2,237
Southbridge Landfill closure charge	2,642	625	$ 3,815	2,097
Multiemployer pension plan, type			us-gaap:PensionPlansDefinedBenefitMember
Multiemployer pension plan, name			us-gaap:RetirementPlanNameOtherMember
Multiemployer pension plan, collective-bargaining arrangement			us-gaap:CollectiveBargainingArrangementOtherMember
Multiemployer pension plan withdrawal obligation		3,194		3,194
Withdrawal costs - multiemployer pension plan	0	3,591	$ 0	3,591
Reversal of pension costs		397		397
Contingent liability term			17 years
Withdrawal obligation, gross payments	4,224		$ 4,224
Estimated accumulated benefit obligation as complete withdrawal	18,511		18,511
Southbridge Landfill
Site Contingency [Line Items]
Southbridge Landfill closure charge	2,642	$ 625	3,815	$ 2,097
Legal and other costs	642		1,851
Loss contingency, settlement awarded	$ 2,000		2,000
Amortization			152
Recovery credited to environmental remediation expense			$ (188)