GOODWILL AND OTHER INTANGIBLE ASSETS - Changes in Carrying Amount of Goodwill (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Goodwill [Roll Forward]
Beginning Balance	$ 3,604.0	$ 3,591.0
Goodwill acquired during year	17.9	46.5
Purchase accounting adjustments	(6.4)	(7.4)
Impairments during the year		(65.0)
Write-offs related to disposition and assets held for sale		(7.1)
Changes due to foreign currency fluctuations	9.7	46.0
Ending Balance	3,625.2	3,604.0
Domestic and Canada RCS
Goodwill [Roll Forward]
Beginning Balance	2,850.2	2,811.8
Goodwill acquired during year	17.9	36.9
Purchase accounting adjustments	(5.4)	(10.1)
Impairments during the year		0.0
Write-offs related to disposition and assets held for sale		0.0
Changes due to foreign currency fluctuations	(3.9)	11.6
Ending Balance	2,858.8	2,850.2
International Regulated Waste And Compliance Services
Goodwill [Roll Forward]
Beginning Balance	466.8	498.4
Goodwill acquired during year	0.0	4.9
Purchase accounting adjustments	(0.2)	1.2
Impairments during the year		(65.0)
Write-offs related to disposition and assets held for sale		(7.1)
Changes due to foreign currency fluctuations	13.6	34.4
Ending Balance	480.2	466.8
All Other
Goodwill [Roll Forward]
Beginning Balance	287.0	280.8
Goodwill acquired during year	0.0	4.7
Purchase accounting adjustments	(0.8)	1.5
Impairments during the year		0.0
Write-offs related to disposition and assets held for sale		0.0
Changes due to foreign currency fluctuations	0.0	0.0
Ending Balance	$ 286.2	$ 287.0