GOODWILL AND OTHER INTANGIBLE ASSETS (Tables)

3 Months Ended

Mar. 31, 2025

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Changes to Goodwill

The changes in goodwill by segment for the three months ended March 31, 2025 were as follows (in thousands):

	Environmental Services		Safety-Kleen Sustainability Solutions		Totals
Balance at January 1, 2025	$	1,296,204	$	180,995	$	1,477,199
Measurement period adjustments from prior period acquisitions	146		(99)		47
Foreign currency translation	44		17		61
Balance at March 31, 2025	$	1,296,394	$	180,913	$	1,477,307

Schedule of Finite-Lived Intangible Assets

As of March 31, 2025 and December 31, 2024, the Company’s intangible assets consisted of the following (in thousands):

	March 31, 2025						December 31, 2024
	Cost		Accumulated Amortization		Net		Cost		Accumulated Amortization		Net
Permits	$	192,010	$	125,528	$	66,482	$	191,921	$	123,939	$	67,982
Customer and supplier relationships	697,353		265,529		431,824		697,326		256,657		440,669
Other intangible assets	120,319		49,189		71,130		120,316		46,490		73,826
Total amortizable permits and other intangible assets	1,009,682		440,246		569,436		1,009,563		427,086		582,477
Trademarks and trade names	119,521		—		119,521		119,510		—		119,510
Total permits and other intangible assets	$	1,129,203	$	440,246	$	688,957	$	1,129,073	$	427,086	$	701,987

Summary of Indefinite-Lived Intangible Assets

As of March 31, 2025 and December 31, 2024, the Company’s intangible assets consisted of the following (in thousands):

	March 31, 2025						December 31, 2024
	Cost		Accumulated Amortization		Net		Cost		Accumulated Amortization		Net
Permits	$	192,010	$	125,528	$	66,482	$	191,921	$	123,939	$	67,982
Customer and supplier relationships	697,353		265,529		431,824		697,326		256,657		440,669
Other intangible assets	120,319		49,189		71,130		120,316		46,490		73,826
Total amortizable permits and other intangible assets	1,009,682		440,246		569,436		1,009,563		427,086		582,477
Trademarks and trade names	119,521		—		119,521		119,510		—		119,510
Total permits and other intangible assets	$	1,129,203	$	440,246	$	688,957	$	1,129,073	$	427,086	$	701,987

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, 2025 was as follows (in thousands):

Years Ending December 31,	Expected Amortization
2025 (nine months)	$	39,804
2026	51,050
2027	48,969
2028	47,659
2029	46,680
Thereafter	335,274
	$	569,436