SEGMENT REPORTING - Reconciliation of Third Party Revenues to Direct Revenues (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Segment Reporting Information [Line Items]
Total revenues	$ 1,431,950	$ 1,376,695
Total Segment Revenues
Segment Reporting Information [Line Items]
Total revenues	1,431,853	1,376,593
Environmental Services
Segment Reporting Information [Line Items]
Total revenues	1,209,113	1,172,510
Safety-Kleen Sustainability Solutions
Segment Reporting Information [Line Items]
Total revenues	222,740	204,083
Operating Segments | Total Segment Revenues
Segment Reporting Information [Line Items]
Total revenues	1,431,853	1,376,593
Operating Segments | Environmental Services
Segment Reporting Information [Line Items]
Total revenues	1,207,038	1,161,279
Operating Segments | Safety-Kleen Sustainability Solutions
Segment Reporting Information [Line Items]
Total revenues	224,815	215,314
Intersegment revenues (expense), net | Environmental Services
Segment Reporting Information [Line Items]
Total revenues	2,075	11,231
Intersegment revenues (expense), net | Safety-Kleen Sustainability Solutions
Segment Reporting Information [Line Items]
Total revenues	(2,075)	(11,231)
Corporate
Segment Reporting Information [Line Items]
Total revenues	$ 97	$ 102