GOODWILL AND OTHER INTANGIBLE ASSETS - Changes to Goodwill (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2024 USD ($)
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 1,287,736
Increase from current period acquisitions	201,009
Measurement period adjustments from prior period acquisitions	218
Foreign currency translation	(1,142)
Goodwill, ending balance	1,487,821
Environmental Services
Goodwill [Roll Forward]
Goodwill, beginning balance	1,112,013
Increase from current period acquisitions	195,265
Measurement period adjustments from prior period acquisitions	218
Foreign currency translation	(815)
Goodwill, ending balance	1,306,681
Safety-Kleen Sustainability Solutions
Goodwill [Roll Forward]
Goodwill, beginning balance	175,723
Increase from current period acquisitions	5,744
Measurement period adjustments from prior period acquisitions	0
Foreign currency translation	(327)
Goodwill, ending balance	$ 181,140