RESTRUCTURING, DIVESTITURES, AND ASSETS HELD FOR SALE - Summary of Non-cash Impairment Charges and Gains or Losses Included in SG&A in the Consolidated Statements of (Loss) Income, Associated With Divestitures (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Restructuring Cost And Reserve [Line Items]
Total	$ 20.5	$ 9.5	$ 27.1
International Regulated Waste And Compliance Services | United Kingdom
Restructuring Cost And Reserve [Line Items]
Non-cash impairment charges	4.2	6.8	3.8
Selling, General and Administrative Expenses
Restructuring Cost And Reserve [Line Items]
Total	12.8	9.5	27.1
Selling, General and Administrative Expenses | Domestic And Canada Regulated Waste And Compliance Services
Restructuring Cost And Reserve [Line Items]
Non-cash impairment charges	6.9
Total	6.9
Selling, General and Administrative Expenses | International Regulated Waste And Compliance Services
Restructuring Cost And Reserve [Line Items]
Non-cash impairment charges	4.2	6.8	25.5
Total	5.9	9.5	27.1
Selling, General and Administrative Expenses | International Regulated Waste And Compliance Services | United Kingdom
Restructuring Cost And Reserve [Line Items]
(Gain) Losses on divestiture of business	$ 1.7	5.7	$ 1.6
Selling, General and Administrative Expenses | International Regulated Waste And Compliance Services | South Africa
Restructuring Cost And Reserve [Line Items]
(Gain) Losses on divestiture of business		$ (3.0)