GOODWILL AND OTHER INTANGIBLE ASSETS - Summary of Remaining Non-Cash Impairment Charges Incurred Due to Certain Operations Across Segments (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Intangible Assets By Major Class [Line Items]
Total Customer Relationships and Operating Permits	$ 16.0	$ 21.0	$ 1.4
Domestic And Canada Regulated Waste And Compliance Services
Intangible Assets By Major Class [Line Items]
Total Customer Relationships and Operating Permits	0.5	3.1
International Regulated Waste And Compliance Services
Intangible Assets By Major Class [Line Items]
Total Customer Relationships and Operating Permits	$ 15.5	12.1	$ 1.4
All Other
Intangible Assets By Major Class [Line Items]
Total Customer Relationships and Operating Permits		$ 5.8