PROPERTY, PLANT AND EQUIPMENT - Schedule of Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 3,699,416	$ 3,593,814
Less - accumulated depreciation and amortization	2,174,118	2,005,663
Total property, plant and equipment, net	1,525,298	1,588,151
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	139,776	131,023
Asset retirement costs (non-landfill)
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	16,407	15,924
Landfill assets
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	191,687	182,276
Buildings and improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	509,804	499,159
Right-of-use assets, finance leases	8,900	31,000
Camp equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	159,021	158,277
Vehicles
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	844,026	785,056
Right-of-use assets, finance leases	47,200	2,400
Equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	1,807,235	1,779,366
Right-of-use assets, finance leases	9,300
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	7,082	6,054
Construction in progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 24,378	$ 36,679