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BUSINESS COMBINATIONS - Narrative (Detail) - business	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Number of businesses acquired	10	9	9
Intangible assets, useful life	10 years
Minimum
Business Acquisition [Line Items]
Intangible assets, useful life	5 years
Maximum
Business Acquisition [Line Items]
Intangible assets, useful life	10 years
Western | Tuck-in Solid Waste Collection Business
Business Acquisition [Line Items]
Number of businesses acquired	7	4
Western | Solid Waste Collection Business
Business Acquisition [Line Items]
Number of businesses acquired			6
Western | Transfer Business
Business Acquisition [Line Items]
Number of businesses acquired			1
Resource Solutions | Recycling Operation
Business Acquisition [Line Items]
Number of businesses acquired	1
Eastern | Tuck-in Solid Waste Collection Business
Business Acquisition [Line Items]
Number of businesses acquired		3
Eastern | Collection and Transfer Business
Business Acquisition [Line Items]
Number of businesses acquired			2

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