GOODWILL AND OTHER INTANGIBLE ASSETS - Changes to Goodwill (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2023 USD ($)
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 1,246,878
Increase from current period acquisition	39,925
Measurement period adjustments from prior period acquisitions	340
Foreign currency translation	1,148
Goodwill, ending balance	1,288,291
Environmental Services
Goodwill [Roll Forward]
Goodwill, beginning balance	1,071,846
Increase from current period acquisition	39,925
Measurement period adjustments from prior period acquisitions	0
Foreign currency translation	818
Goodwill, ending balance	1,112,589
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	340
Foreign currency translation	330
Goodwill, ending balance	$ 175,702