REVENUES - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Disaggregation of Revenue [Line Items]
Total revenues	$ 1,529,422	$ 1,365,696	$ 4,458,836	$ 4,070,983
Technical Services
Disaggregation of Revenue [Line Items]
Total revenues	437,180	403,889	1,288,339	1,160,306
Industrial Services and Other
Disaggregation of Revenue [Line Items]
Total revenues	345,669	350,363	1,064,738	1,086,510
Field and Emergency Response Services
Disaggregation of Revenue [Line Items]
Total revenues	260,200	155,046	676,562	457,491
Safety-Kleen Environmental Services
Disaggregation of Revenue [Line Items]
Total revenues	304,372	285,551	888,002	825,240
Safety-Kleen Oil
Disaggregation of Revenue [Line Items]
Total revenues	182,001	170,847	541,195	541,436
United States
Disaggregation of Revenue [Line Items]
Total revenues	1,385,719	1,224,196	4,041,407	3,659,507
Canada
Disaggregation of Revenue [Line Items]
Total revenues	143,703	141,500	417,429	411,476
Environmental Services
Disaggregation of Revenue [Line Items]
Total revenues	1,297,187	1,146,363	3,779,080	3,389,140
Safety-Kleen Sustainability Solutions
Disaggregation of Revenue [Line Items]
Total revenues	232,139	219,221	679,459	681,508
Operating Segments | Environmental Services
Disaggregation of Revenue [Line Items]
Total revenues	1,287,650	1,135,279	3,746,227	3,357,743
Operating Segments | Environmental Services | Technical Services
Disaggregation of Revenue [Line Items]
Total revenues	437,180	403,889	1,288,339	1,160,306
Operating Segments | Environmental Services | Industrial Services and Other
Disaggregation of Revenue [Line Items]
Total revenues	345,573	350,251	1,064,441	1,086,175
Operating Segments | Environmental Services | Field and Emergency Response Services
Disaggregation of Revenue [Line Items]
Total revenues	260,200	155,046	676,562	457,491
Operating Segments | Environmental Services | Safety-Kleen Environmental Services
Disaggregation of Revenue [Line Items]
Total revenues	244,697	226,093	716,885	653,771
Operating Segments | Environmental Services | Safety-Kleen Oil
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0	0
Operating Segments | Environmental Services | United States
Disaggregation of Revenue [Line Items]
Total revenues	1,166,660	1,017,224	3,395,446	3,017,547
Operating Segments | Environmental Services | Canada
Disaggregation of Revenue [Line Items]
Total revenues	120,990	118,055	350,781	340,196
Operating Segments | Safety-Kleen Sustainability Solutions
Disaggregation of Revenue [Line Items]
Total revenues	241,676	230,305	712,312	712,905
Operating Segments | Safety-Kleen Sustainability Solutions | Technical Services
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0	0
Operating Segments | Safety-Kleen Sustainability Solutions | Industrial Services and Other
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0	0
Operating Segments | Safety-Kleen Sustainability Solutions | Field and Emergency Response Services
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0	0
Operating Segments | Safety-Kleen Sustainability Solutions | Safety-Kleen Environmental Services
Disaggregation of Revenue [Line Items]
Total revenues	59,675	59,458	171,117	171,469
Operating Segments | Safety-Kleen Sustainability Solutions | Safety-Kleen Oil
Disaggregation of Revenue [Line Items]
Total revenues	182,001	170,847	541,195	541,436
Operating Segments | Safety-Kleen Sustainability Solutions | United States
Disaggregation of Revenue [Line Items]
Total revenues	218,963	206,860	645,664	641,625
Operating Segments | Safety-Kleen Sustainability Solutions | Canada
Disaggregation of Revenue [Line Items]
Total revenues	22,713	23,445	66,648	71,280
Corporate
Disaggregation of Revenue [Line Items]
Total revenues	96	112	297	335
Corporate | Technical Services
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0	0
Corporate | Industrial Services and Other
Disaggregation of Revenue [Line Items]
Total revenues	96	112	297	335
Corporate | Field and Emergency Response Services
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0	0
Corporate | Safety-Kleen Environmental Services
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0	0
Corporate | Safety-Kleen Oil
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0	0
Corporate | United States
Disaggregation of Revenue [Line Items]
Total revenues	96	112	297	335
Corporate | Canada
Disaggregation of Revenue [Line Items]
Total revenues	$ 0	$ 0	$ 0	$ 0