GOODWILL AND OTHER INTANGIBLE ASSETS - Changes to Goodwill (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2024 USD ($)
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 1,287,736
Increase from current period acquisitions	195,789
Measurement period adjustments from prior period acquisitions	218
Foreign currency translation	(1,658)
Goodwill, ending balance	1,482,085
Environmental Services
Goodwill [Roll Forward]
Goodwill, beginning balance	1,112,013
Increase from current period acquisitions	193,712
Measurement period adjustments from prior period acquisitions	218
Foreign currency translation	(1,181)
Goodwill, ending balance	1,304,762
Safety-Kleen Sustainability Solutions
Goodwill [Roll Forward]
Goodwill, beginning balance	175,723
Increase from current period acquisitions	2,077
Measurement period adjustments from prior period acquisitions	0
Foreign currency translation	(477)
Goodwill, ending balance	$ 177,323