BUSINESS COMBINATIONS - Narrative (Details) - business	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Business Acquisition [Line Items]
Number of businesses acquired	6	8
Minimum
Business Acquisition [Line Items]
Useful life of finite lived intangible assets	5 years
Maximum
Business Acquisition [Line Items]
Useful life of finite lived intangible assets	10 years
Western | Tuck-in Solid Waste Collection Business
Business Acquisition [Line Items]
Number of businesses acquired	5	3
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