GOODWILL AND OTHER INTANGIBLE ASSETS (Tables)

6 Months Ended

Jun. 30, 2023

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Changes to Goodwill

The changes in goodwill by segment for the six months ended June 30, 2023 were as follows (in thousands):

	Environmental Services		Safety-Kleen Sustainability Solutions		Totals
Balance at January 1, 2023	$	1,071,846	$	175,032	$	1,246,878
Increase from current period acquisition	39,925		—		39,925
Measurement period adjustments from prior period acquisitions	—		340		340
Foreign currency translation	818		330		1,148
Balance at June 30, 2023	$	1,112,589	$	175,702	$	1,288,291

Schedule of Finite-Lived Intangible Assets

As of June 30, 2023 and December 31, 2022, the Company's intangible assets consisted of the following (in thousands):

	June 30, 2023						December 31, 2022
	Cost		Accumulated Amortization		Net		Cost		Accumulated Amortization		Net
Permits	$	190,209	$	113,404	$	76,805	$	188,373	$	109,036	$	79,337
Customer and supplier relationships	604,992		244,537		360,455		583,709		229,368		354,341
Other intangible assets	100,068		31,291		68,777		89,388		24,818		64,570
Total amortizable permits and other intangible assets	895,269		389,232		506,037		861,470		363,222		498,248
Trademarks and trade names	120,283		—		120,283		122,534		—		122,534
Total permits and other intangible assets	$	1,015,552	$	389,232	$	626,320	$	984,004	$	363,222	$	620,782

Summary of Indefinite-Lived Intangible Assets

As of June 30, 2023 and December 31, 2022, the Company's intangible assets consisted of the following (in thousands):

	June 30, 2023						December 31, 2022
	Cost		Accumulated Amortization		Net		Cost		Accumulated Amortization		Net
Permits	$	190,209	$	113,404	$	76,805	$	188,373	$	109,036	$	79,337
Customer and supplier relationships	604,992		244,537		360,455		583,709		229,368		354,341
Other intangible assets	100,068		31,291		68,777		89,388		24,818		64,570
Total amortizable permits and other intangible assets	895,269		389,232		506,037		861,470		363,222		498,248
Trademarks and trade names	120,283		—		120,283		122,534		—		122,534
Total permits and other intangible assets	$	1,015,552	$	389,232	$	626,320	$	984,004	$	363,222	$	620,782

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, 2023 was as follows (in thousands):

Years Ending December 31,	Expected Amortization
2023 (six months)	$	24,894
2024	46,461
2025	43,036
2026	41,146
2027	39,067
Thereafter	311,433
	$	506,037