SEGMENT REPORTING - Adjusted EBITDA and Significant Segment Expense Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Segment Reporting Information [Line Items]
Direct Revenues	$ 5,889,952	$ 5,409,152	$ 5,166,605
Cost of Revenues	4,065,713	3,746,124	3,543,930
Selling, general and administrative expenses	739,629	671,161	627,391
Total Reportable Segments
Segment Reporting Information [Line Items]
Direct Revenues	5,889,545	5,408,705	5,166,098
Cost of Revenues	4,025,239	3,709,344	3,518,282
Selling, general and administrative expenses	449,838	424,880	388,436
Total Reportable Segment Adjusted EBITDA	1,414,468	1,274,481	1,259,380
Environmental Services
Segment Reporting Information [Line Items]
Direct Revenues	5,004,747	4,511,442	4,171,706
Cost of Revenues	3,366,022	3,063,043	2,902,979
Selling, general and administrative expenses	371,263	346,791	315,674
Total Reportable Segment Adjusted EBITDA	1,267,462	1,101,608	953,053
Safety-Kleen Sustainability Solutions
Segment Reporting Information [Line Items]
Direct Revenues	884,798	897,263	994,392
Cost of Revenues	659,217	646,301	615,303
Selling, general and administrative expenses	78,575	78,089	72,762
Total Reportable Segment Adjusted EBITDA	$ 147,006	$ 172,873	$ 306,327