GOODWILL AND OTHER INTANGIBLE ASSETS (Tables)

3 Months Ended

Mar. 31, 2023

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Changes to Goodwill

The changes in goodwill by segment for the three months ended March 31, 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	40,092		—		40,092
Measurement period adjustments from prior period acquisitions	—		396		396
Foreign currency translation	36		14		50
Balance at March 31, 2023	$	1,111,974	$	175,442	$	1,287,416

Schedule of Finite-Lived Intangible Assets

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

	March 31, 2023						December 31, 2022
	Cost		Accumulated Amortization		Net		Cost		Accumulated Amortization		Net
Permits	$	188,736	$	111,080	$	77,656	$	188,373	$	109,036	$	79,337
Customer and supplier relationships	603,734		236,976		366,758		583,709		229,368		354,341
Other intangible assets	99,906		27,926		71,980		89,388		24,818		64,570
Total amortizable permits and other intangible assets	892,376		375,982		516,394		861,470		363,222		498,248
Trademarks and trade names	120,129		—		120,129		122,534		—		122,534
Total permits and other intangible assets	$	1,012,505	$	375,982	$	636,523	$	984,004	$	363,222	$	620,782

Summary of Indefinite-Lived Intangible Assets

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

	March 31, 2023						December 31, 2022
	Cost		Accumulated Amortization		Net		Cost		Accumulated Amortization		Net
Permits	$	188,736	$	111,080	$	77,656	$	188,373	$	109,036	$	79,337
Customer and supplier relationships	603,734		236,976		366,758		583,709		229,368		354,341
Other intangible assets	99,906		27,926		71,980		89,388		24,818		64,570
Total amortizable permits and other intangible assets	892,376		375,982		516,394		861,470		363,222		498,248
Trademarks and trade names	120,129		—		120,129		122,534		—		122,534
Total permits and other intangible assets	$	1,012,505	$	375,982	$	636,523	$	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 March 31, 2023 was as follows (in thousands):

Years Ending December 31,	Expected Amortization
2023 (nine months)	$	36,778
2024	45,626
2025	42,433
2026	40,545
2027	38,469
Thereafter	312,543
	$	516,394