SEGMENT REPORTING - Reconciliation to Consolidated Statements of Income to Adjusted EBITDA (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Segment Reporting Information [Line Items]
Adjusted EBITDA	$ 230,095	$ 215,138
Reconciliation to Consolidated Statements of Operations:
Accretion of environmental liabilities	3,217	3,407
Stock-based compensation	6,338	6,018
Depreciation and amortization	95,065	84,758
Income from operations	125,475	120,955
Other expense (income), net	1,141	(116)
Loss on early extinguishment of debt	0	2,362
Interest expense, net of interest income	28,539	20,632
Income before provision for income taxes	95,795	98,077
Operating Segments | Environmental Services
Segment Reporting Information [Line Items]
Adjusted EBITDA	264,475	228,345
Operating Segments | Safety-Kleen Sustainability Solutions
Segment Reporting Information [Line Items]
Adjusted EBITDA	29,700	41,463
Corporate
Segment Reporting Information [Line Items]
Adjusted EBITDA	$ (64,080)	$ (54,670)