REVENUES - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Disaggregation of Revenue [Line Items]
Total revenues	$ 5,889,952	$ 5,409,152	$ 5,166,605
Technical Services
Disaggregation of Revenue [Line Items]
Total revenues	1,733,550	1,563,847	1,495,264
Industrial Services and Other
Disaggregation of Revenue [Line Items]
Total revenues	1,377,909	1,419,385	1,311,579
Field and Emergency Response Services
Disaggregation of Revenue [Line Items]
Total revenues	895,120	609,913	575,300
Safety-Kleen Environmental Services
Disaggregation of Revenue [Line Items]
Total revenues	1,183,883	1,102,041	962,697
Safety-Kleen Oil
Disaggregation of Revenue [Line Items]
Total revenues	699,490	713,966	821,765
United States
Disaggregation of Revenue [Line Items]
Total revenues	5,352,423	4,869,180	4,576,167
Canada
Disaggregation of Revenue [Line Items]
Total revenues	537,529	539,972	590,438
Environmental Services
Disaggregation of Revenue [Line Items]
Total revenues	5,004,747	4,511,442	4,171,706
Safety-Kleen Sustainability Solutions
Disaggregation of Revenue [Line Items]
Total revenues	884,798	897,263	994,392
Operating segments | Environmental Services
Disaggregation of Revenue [Line Items]
Total revenues	4,960,325	4,469,909	4,144,973
Operating segments | Environmental Services | Technical Services
Disaggregation of Revenue [Line Items]
Total revenues	1,733,550	1,563,847	1,495,264
Operating segments | Environmental Services | Industrial Services and Other
Disaggregation of Revenue [Line Items]
Total revenues	1,377,502	1,418,938	1,311,072
Operating segments | Environmental Services | Field and Emergency Response Services
Disaggregation of Revenue [Line Items]
Total revenues	895,120	609,913	575,300
Operating segments | Environmental Services | Safety-Kleen Environmental Services
Disaggregation of Revenue [Line Items]
Total revenues	954,153	877,211	763,337
Operating segments | Environmental Services | Safety-Kleen Oil
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0
Operating segments | Environmental Services | United States
Disaggregation of Revenue [Line Items]
Total revenues	4,510,845	4,022,394	3,675,880
Operating segments | Environmental Services | Canada
Disaggregation of Revenue [Line Items]
Total revenues	449,480	447,515	469,093
Operating segments | Safety-Kleen Sustainability Solutions
Disaggregation of Revenue [Line Items]
Total revenues	929,220	938,796	1,021,125
Operating segments | Safety-Kleen Sustainability Solutions | Technical Services
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0
Operating segments | Safety-Kleen Sustainability Solutions | Industrial Services and Other
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0
Operating segments | Safety-Kleen Sustainability Solutions | Field and Emergency Response Services
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0
Operating segments | Safety-Kleen Sustainability Solutions | Safety-Kleen Environmental Services
Disaggregation of Revenue [Line Items]
Total revenues	229,730	224,830	199,360
Operating segments | Safety-Kleen Sustainability Solutions | Safety-Kleen Oil
Disaggregation of Revenue [Line Items]
Total revenues	699,490	713,966	821,765
Operating segments | Safety-Kleen Sustainability Solutions | United States
Disaggregation of Revenue [Line Items]
Total revenues	841,171	846,339	899,780
Operating segments | Safety-Kleen Sustainability Solutions | Canada
Disaggregation of Revenue [Line Items]
Total revenues	88,049	92,457	121,345
Corporate
Disaggregation of Revenue [Line Items]
Total revenues	407	447	507
Corporate | Technical Services
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0
Corporate | Industrial Services and Other
Disaggregation of Revenue [Line Items]
Total revenues	407	447	507
Corporate | Field and Emergency Response Services
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0
Corporate | Safety-Kleen Environmental Services
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0
Corporate | Safety-Kleen Oil
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0
Corporate | United States
Disaggregation of Revenue [Line Items]
Total revenues	407	447	507
Corporate | Canada
Disaggregation of Revenue [Line Items]
Total revenues	$ 0	$ 0	$ 0