GOODWILL AND OTHER INTANGIBLE ASSETS (Tables)

6 Months Ended

Jun. 30, 2024

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Changes to Goodwill

The changes in goodwill by segment for the six months ended June 30, 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	193,712		2,077		195,789
Measurement period adjustments from prior period acquisitions	218		—		218
Foreign currency translation	(1,181)		(477)		(1,658)
Balance at June 30, 2024	$	1,304,762	$	177,323	$	1,482,085

Schedule of Finite-Lived Intangible Assets

As of June 30, 2024 and December 31, 2023, the Company’s intangible assets consisted of the following (in thousands):

	June 30, 2024						December 31, 2023
	Cost		Accumulated Amortization		Net		Cost		Accumulated Amortization		Net
Permits	$	192,138	$	121,085	$	71,053	$	191,747	$	117,556	$	74,191
Customer and supplier relationships	706,721		244,082		462,639		604,994		258,879		346,115
Other intangible assets	114,078		40,281		73,797		100,068		37,862		62,206
Total amortizable permits and other intangible assets	1,012,937		405,448		607,489		896,809		414,297		482,512
Trademarks and trade names	119,974		—		119,974		120,285		—		120,285
Total permits and other intangible assets	$	1,132,911	$	405,448	$	727,463	$	1,017,094	$	414,297	$	602,797

Summary of Indefinite-Lived Intangible Assets

As of June 30, 2024 and December 31, 2023, the Company’s intangible assets consisted of the following (in thousands):

	June 30, 2024						December 31, 2023
	Cost		Accumulated Amortization		Net		Cost		Accumulated Amortization		Net
Permits	$	192,138	$	121,085	$	71,053	$	191,747	$	117,556	$	74,191
Customer and supplier relationships	706,721		244,082		462,639		604,994		258,879		346,115
Other intangible assets	114,078		40,281		73,797		100,068		37,862		62,206
Total amortizable permits and other intangible assets	1,012,937		405,448		607,489		896,809		414,297		482,512
Trademarks and trade names	119,974		—		119,974		120,285		—		120,285
Total permits and other intangible assets	$	1,132,911	$	405,448	$	727,463	$	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 June 30, 2024 was as follows (in thousands):

Years Ending December 31,	Expected Amortization
2024 (six months)	$	27,418
2025	52,546
2026	50,657
2027	48,576
2028	47,260
Thereafter	381,032
	$	607,489