PROPERTY, PLANT AND EQUIPMENT (Schedule of Property, Plant and Equipment) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	$ 3,424,237	$ 3,332,595
Less - accumulated depreciation and amortization	1,835,624	1,770,617
Total property, plant and equipment, net	1,588,613	1,561,978
Land
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	129,684	123,734
Asset retirement costs (non-landfill)
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	15,258	15,148
Landfill assets
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	160,093	154,918
Buildings and improvements
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	465,707	440,188
Camp equipment
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	156,031	152,998
Vehicles
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	753,490	721,735
Equipment
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	1,711,470	1,697,490
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	5,476	5,453
Construction in progress
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	$ 27,028	$ 20,931