SEGMENT REPORTING - Reconciliation of Third Party Revenues to Direct Revenues (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Segment Reporting Information [Line Items]
Total revenues	$ 1,552,719	$ 1,397,900	$ 2,929,414	$ 2,705,287
Environmental Services
Segment Reporting Information [Line Items]
Total revenues	1,309,383	1,172,036	2,481,893	2,242,777
Safety-Kleen Sustainability Solutions
Segment Reporting Information [Line Items]
Total revenues	243,237	225,748	447,320	462,287
Operating Segments | Environmental Services
Segment Reporting Information [Line Items]
Total revenues	1,297,298	1,161,482	2,458,577	2,222,464
Operating Segments | Safety-Kleen Sustainability Solutions
Segment Reporting Information [Line Items]
Total revenues	255,322	236,302	470,636	482,600
Intersegment Revenues (Expenses), net | Environmental Services
Segment Reporting Information [Line Items]
Total revenues	12,085	10,554	23,316	20,313
Intersegment Revenues (Expenses), net | Safety-Kleen Sustainability Solutions
Segment Reporting Information [Line Items]
Total revenues	(12,085)	(10,554)	(23,316)	(20,313)
Corporate
Segment Reporting Information [Line Items]
Total revenues	$ 99	$ 116	$ 201	$ 223