PROPERTY, PLANT AND EQUIPMENT (Schedule of Property, Plant and Equipment) (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	$ 3,286,569	$ 3,190,573
Less - accumulated depreciation and amortization	1,677,187	1,603,208
Total property, plant and equipment, net	1,609,382	1,587,365
Land
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	123,984	121,658
Asset retirement costs (non-landfill)
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	14,780	14,593
Landfill assets
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	145,068	144,539
Buildings and improvements
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	429,880	414,384
Camp equipment
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	161,899	170,012
Vehicles
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	689,846	617,959
Equipment
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	1,675,920	1,644,102
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	5,623	5,708
Construction in progress
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	$ 39,569	$ 57,618