GOODWILL AND OTHER INTANGIBLE ASSETS - Changes to Goodwill (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($)
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 1,246,878
Increase from current period acquisition	40,092
Measurement period adjustments from prior period acquisitions	396
Foreign currency translation	50
Goodwill, ending balance	1,287,416
Environmental Services
Goodwill [Roll Forward]
Goodwill, beginning balance	1,071,846
Increase from current period acquisition	40,092
Measurement period adjustments from prior period acquisitions	0
Foreign currency translation	36
Goodwill, ending balance	1,111,974
Safety-Kleen Sustainability Solutions
Goodwill [Roll Forward]
Goodwill, beginning balance	175,032
Increase from current period acquisition	0
Measurement period adjustments from prior period acquisitions	396
Foreign currency translation	14
Goodwill, ending balance	$ 175,442