PROPERTY, PLANT AND EQUIPMENT - Schedule of Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	$ 3,496,303	$ 3,332,595
Less - accumulated depreciation and amortization	1,899,386	1,770,617
Total property, plant and equipment, net	1,596,917	1,561,978
Land
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	134,306	123,734
Asset retirement costs (non-landfill)
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	15,358	15,148
Landfill assets
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	164,816	154,918
Buildings and improvements
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	472,383	440,188
Camp equipment
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	158,992	152,998
Vehicles
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	777,968	721,735
Equipment
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	1,732,020	1,697,490
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	5,511	5,453
Construction in progress
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	$ 34,949	$ 20,931