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GOODWILL AND INTANGIBLE ASSETS - Schedule of Activity and Balances Related to Goodwill by Operating Segment (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2018 USD ($)
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 122,605
Acquisitions	28,424
Goodwill, ending balance	151,029
Eastern
Goodwill [Roll Forward]
Goodwill, beginning balance	19,192
Acquisitions	5,601
Goodwill, ending balance	24,793
Eastern | Complete Acquisition
Goodwill [Roll Forward]
Acquisitions	1,230
Western
Goodwill [Roll Forward]
Goodwill, beginning balance	89,369
Acquisitions	22,823
Goodwill, ending balance	112,192
Recycling
Goodwill [Roll Forward]
Goodwill, beginning balance	12,315
Acquisitions	0
Goodwill, ending balance	12,315
Other
Goodwill [Roll Forward]
Goodwill, beginning balance	1,729
Acquisitions	0
Goodwill, ending balance	$ 1,729

X

- Definition

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975

+ Details

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Balance Type:	debit
Period Type:	instant

X

- Definition

Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

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X

- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

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X

- Details

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- Details

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- Details

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