GOODWILL AND OTHER INTANGIBLE ASSETS (Tables)

3 Months Ended

Mar. 31, 2022

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Changes to Goodwill

The changes in goodwill by segment for the three months ended March 31, 2022 were as follows (in thousands):

	Environmental Services		Safety-Kleen Sustainability Solutions		Totals
Balance at January 1, 2022	$	1,085,534	$	141,508	$	1,227,042
Measurement period adjustments from prior period acquisitions	(6,557)		—		(6,557)
Foreign currency translation	671		243		914
Balance at March 31, 2022	$	1,079,648	$	141,751	$	1,221,399

Schedule of Finite-Lived Intangible Assets

As of March 31, 2022 and December 31, 2021, the Company's intangible assets consisted of the following (in thousands):

	March 31, 2022						December 31, 2021
	Cost		Accumulated Amortization		Net		Cost		Accumulated Amortization		Net
Permits	$	188,204	$	104,586	$	83,618	$	187,519	$	102,408	$	85,111
Customer and supplier relationships	577,017		222,560		354,457		576,474		214,776		361,698
Other intangible assets	94,357		22,340		72,017		94,271		19,359		74,912
Total amortizable permits and other intangible assets	859,578		349,486		510,092		858,264		336,543		521,721
Trademarks and trade names	123,353		—		123,353		123,191		—		123,191
Total permits and other intangible assets	$	982,931	$	349,486	$	633,445	$	981,455	$	336,543	$	644,912

Summary of Indefinite-Lived Intangible Assets

As of March 31, 2022 and December 31, 2021, the Company's intangible assets consisted of the following (in thousands):

	March 31, 2022						December 31, 2021
	Cost		Accumulated Amortization		Net		Cost		Accumulated Amortization		Net
Permits	$	188,204	$	104,586	$	83,618	$	187,519	$	102,408	$	85,111
Customer and supplier relationships	577,017		222,560		354,457		576,474		214,776		361,698
Other intangible assets	94,357		22,340		72,017		94,271		19,359		74,912
Total amortizable permits and other intangible assets	859,578		349,486		510,092		858,264		336,543		521,721
Trademarks and trade names	123,353		—		123,353		123,191		—		123,191
Total permits and other intangible assets	$	982,931	$	349,486	$	633,445	$	981,455	$	336,543	$	644,912

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, 2022 was as follows (in thousands):

Years Ending December 31,	Expected Amortization
2022 (nine months)	$	36,803
2023	44,826
2024	39,342
2025	38,132
2026	36,328
Thereafter	314,661
	$	510,092