PROPERTY, PLANT, AND EQUIPMENT (Tables)

12 Months Ended

Dec. 31, 2018

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment

The Company depreciates and amortizes the cost of these assets, using the straight-line method as follows:

Asset Classification	Estimated Useful Life
Buildings and building improvements
Buildings	20–42 years
Leasehold and building improvements	2–45 years
Camp and lodging equipment	8–15 years
Vehicles	2–15 years
Equipment
Capitalized software and computer equipment	3–5 years
Containers and railcars	8–16 years
All other equipment	4–30 years
Furniture and fixtures	5–8 years

Property, plant and equipment consisted of the following (in thousands):

	December 31, 2018		December 31, 2017
Land	$	123,734	$	121,658
Asset retirement costs (non-landfill)	15,148		14,593
Landfill assets	154,918		144,539
Buildings and improvements	440,188		414,384
Camp and lodging equipment	152,998		170,012
Vehicles	721,735		617,959
Equipment	1,697,490		1,644,102
Furniture and fixtures	5,453		5,708
Construction in progress	20,931		57,618
	3,332,595		3,190,573
Less - accumulated depreciation and amortization	1,770,617		1,603,208
Total property, plant and equipment, net	$	1,561,978	$	1,587,365