GOODWILL AND INTANGIBLE ASSETS - Summary of Goodwill Activity (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2019 USD ($)
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 162,734
Acquisitions	24,180
Other	(2,619)
Goodwill, ending balance	184,295
Eastern
Goodwill [Roll Forward]
Goodwill, beginning balance	28,154
Acquisitions	2,566
Other	0
Goodwill, ending balance	30,720
Western
Goodwill [Roll Forward]
Goodwill, beginning balance	120,536
Acquisitions	21,614
Other	(2,619)
Goodwill, ending balance	139,531
Recycling
Goodwill [Roll Forward]
Goodwill, beginning balance	12,315
Acquisitions	0
Other	0
Goodwill, ending balance	12,315
Other
Goodwill [Roll Forward]
Goodwill, beginning balance	1,729
Acquisitions	0
Other	0
Goodwill, ending balance	$ 1,729