REVENUES FROM CONTRACTS WITH CUSTOMERS - Schedule of Revenues Disaggregated by Service, Primary Geographical Regions and Timing of Revenue Recognition (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Disaggregation of Revenue [Line Items]
Revenues	$ 679.8	$ 672.7	$ 1,344.0	$ 1,340.7
Regulated Waste and Compliance Services
Disaggregation of Revenue [Line Items]
Revenues	448.4	463.0	901.2	936.6
Secure Information Destruction Services
Disaggregation of Revenue [Line Items]
Revenues	231.4	209.7	442.8	404.1
North America
Disaggregation of Revenue [Line Items]
Revenues	568.6	542.6	1,112.3	1,076.3
North America | Regulated Waste and Compliance Services
Disaggregation of Revenue [Line Items]
Revenues	365.6	362.2	727.8	729.0
North America | Secure Information Destruction Services
Disaggregation of Revenue [Line Items]
Revenues	203.0	180.4	384.5	347.3
International
Disaggregation of Revenue [Line Items]
Revenues	111.2	130.1	231.7	264.4
International | Regulated Waste and Compliance Services
Disaggregation of Revenue [Line Items]
Revenues	82.8	100.8	173.4	207.6
International | Secure Information Destruction Services
Disaggregation of Revenue [Line Items]
Revenues	$ 28.4	$ 29.3	$ 58.3	$ 56.8