SEGMENT REPORTING - Reconciliation of Third Party Revenues to Direct Revenues (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Segment Reporting Information [Line Items]
Total revenues	$ 1,529,422	$ 1,365,696	$ 4,458,836	$ 4,070,983
Environmental Services
Segment Reporting Information [Line Items]
Total revenues	1,297,187	1,146,363	3,779,080	3,389,140
Safety-Kleen Sustainability Solutions
Segment Reporting Information [Line Items]
Total revenues	232,139	219,221	679,459	681,508
Operating Segments | Environmental Services
Segment Reporting Information [Line Items]
Total revenues	1,287,650	1,135,279	3,746,227	3,357,743
Operating Segments | Safety-Kleen Sustainability Solutions
Segment Reporting Information [Line Items]
Total revenues	241,676	230,305	712,312	712,905
Intersegment Revenues (Expenses), net | Environmental Services
Segment Reporting Information [Line Items]
Total revenues	9,537	11,084	32,853	31,397
Intersegment Revenues (Expenses), net | Safety-Kleen Sustainability Solutions
Segment Reporting Information [Line Items]
Total revenues	(9,537)	(11,084)	(32,853)	(31,397)
Corporate
Segment Reporting Information [Line Items]
Total revenues	$ 96	$ 112	$ 297	$ 335