SEGMENT REPORTING - Reconciliation of Third Party Revenues to Direct Revenues (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Segment Reporting Information [Line Items]
Total revenues	$ 1,376,695	$ 1,307,387
Environmental Services
Segment Reporting Information [Line Items]
Total revenues	1,172,510	1,070,741
Safety-Kleen Sustainability Solutions
Segment Reporting Information [Line Items]
Total revenues	204,083	236,539
Operating Segments | Environmental Services
Segment Reporting Information [Line Items]
Total revenues	1,161,279	1,060,982
Operating Segments | Safety-Kleen Sustainability Solutions
Segment Reporting Information [Line Items]
Total revenues	215,314	246,298
Intersegment Revenues (Expenses), net | Environmental Services
Segment Reporting Information [Line Items]
Total revenues	11,231	9,759
Intersegment Revenues (Expenses), net | Safety-Kleen Sustainability Solutions
Segment Reporting Information [Line Items]
Total revenues	(11,231)	(9,759)
Corporate
Segment Reporting Information [Line Items]
Total revenues	$ 102	$ 107