SEGMENT REPORTING - Reconciliation of Third Party Revenues to Direct Revenues (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting Information [Line Items]
Total revenues	$ 5,409,152	$ 5,166,605	$ 3,805,566
Environmental Services
Segment Reporting Information [Line Items]
Total revenues	4,511,442	4,171,706	3,032,454
Safety-Kleen Sustainability Solutions
Segment Reporting Information [Line Items]
Total revenues	897,263	994,392	772,813
Operating segments | Environmental Services
Segment Reporting Information [Line Items]
Total revenues	4,469,909	4,144,973	3,025,907
Operating segments | Safety-Kleen Sustainability Solutions
Segment Reporting Information [Line Items]
Total revenues	938,796	1,021,125	779,360
Intersegment revenues (expense), net | Environmental Services
Segment Reporting Information [Line Items]
Total revenues	41,533	26,733	6,547
Intersegment revenues (expense), net | Safety-Kleen Sustainability Solutions
Segment Reporting Information [Line Items]
Total revenues	(41,533)	(26,733)	(6,547)
Corporate Items
Segment Reporting Information [Line Items]
Total revenues	$ 447	$ 507	$ 299