GOODWILL AND OTHER INTANGIBLE ASSETS (Tables)

3 Months Ended

Mar. 31, 2024

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Changes to Goodwill

The changes in goodwill by segment for the three months ended March 31, 2024 were as follows (in thousands):

	Environmental Services		Safety-Kleen Sustainability Solutions		Totals
Balance at January 1, 2024	$	1,112,013	$	175,723	$	1,287,736
Increase from current period acquisitions	195,265		5,744		201,009
Measurement period adjustments from prior period acquisitions	218		—		218
Foreign currency translation	(815)		(327)		(1,142)
Balance at March 31, 2024	$	1,306,681	$	181,140	$	1,487,821

Schedule of Finite-Lived Intangible Assets

As of March 31, 2024 and December 31, 2023, the Company’s intangible assets consisted of the following (in thousands):

	March 31, 2024						December 31, 2023
	Cost		Accumulated Amortization		Net		Cost		Accumulated Amortization		Net
Permits	$	191,130	$	119,219	$	71,911	$	191,747	$	117,556	$	74,191
Customer and supplier relationships	739,675		262,894		476,781		604,994		258,879		346,115
Other intangible assets	112,336		41,123		71,213		100,068		37,862		62,206
Total amortizable permits and other intangible assets	1,043,141		423,236		619,905		896,809		414,297		482,512
Trademarks and trade names	120,070		—		120,070		120,285		—		120,285
Total permits and other intangible assets	$	1,163,211	$	423,236	$	739,975	$	1,017,094	$	414,297	$	602,797

Summary of Indefinite-Lived Intangible Assets

As of March 31, 2024 and December 31, 2023, the Company’s intangible assets consisted of the following (in thousands):

	March 31, 2024						December 31, 2023
	Cost		Accumulated Amortization		Net		Cost		Accumulated Amortization		Net
Permits	$	191,130	$	119,219	$	71,911	$	191,747	$	117,556	$	74,191
Customer and supplier relationships	739,675		262,894		476,781		604,994		258,879		346,115
Other intangible assets	112,336		41,123		71,213		100,068		37,862		62,206
Total amortizable permits and other intangible assets	1,043,141		423,236		619,905		896,809		414,297		482,512
Trademarks and trade names	120,070		—		120,070		120,285		—		120,285
Total permits and other intangible assets	$	1,163,211	$	423,236	$	739,975	$	1,017,094	$	414,297	$	602,797

Schedule of Expected Amortization for the Net Carrying Amount of Finite Lived Intangible Assets

The expected amortization of the net carrying amount of finite-lived intangible assets at March 31, 2024 was as follows (in thousands):

Years Ending December 31,	Expected Amortization
2024 (nine months)	$	37,463
2025	47,957
2026	45,383
2027	43,304
2028	42,044
Thereafter	403,754
	$	619,905