PROPERTY, PLANT AND EQUIPMENT - Schedule of Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 3,606,193	$ 3,593,814
Less - accumulated depreciation and amortization	2,052,385	2,005,663
Total property, plant and equipment, net	1,553,808	1,588,151
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	139,859	131,023
Asset retirement costs (non-landfill)
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	16,102	15,924
Landfill assets
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	182,287	182,276
Buildings and improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	499,701	499,159
Right-of-Use assets, finance leases	8,000	31,000
Camp equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	153,980	158,277
Vehicles
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	809,790	785,056
Right-of-Use assets, finance leases	37,600	2,400
Equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	1,776,574	1,779,366
Right-of-Use assets, finance leases	3,300
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	6,860	6,054
Construction in progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 21,040	$ 36,679