GOODWILL AND OTHER INTANGIBLE ASSETS - Changes to Goodwill (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2024 USD ($)
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 1,287,736
Increase from current period acquisitions	198,156
Measurement period adjustments from prior period acquisitions	218
Foreign currency translation	(1,045)
Goodwill, ending balance	1,485,065
Environmental Services
Goodwill [Roll Forward]
Goodwill, beginning balance	1,112,013
Increase from current period acquisitions	194,845
Measurement period adjustments from prior period acquisitions	218
Foreign currency translation	(745)
Goodwill, ending balance	1,306,331
Safety-Kleen Sustainability Solutions
Goodwill [Roll Forward]
Goodwill, beginning balance	175,723
Increase from current period acquisitions	3,311
Measurement period adjustments from prior period acquisitions	0
Foreign currency translation	(300)
Goodwill, ending balance	$ 178,734