GOODWILL AND OTHER INTANGIBLE ASSETS (Tables)

9 Months Ended

Sep. 30, 2021

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Changes to Goodwill

The changes in goodwill by segment for the nine months ended September 30, 2021 were as follows (in thousands):

	Environmental Services		Safety-Kleen Sustainability Solutions		Totals
Balance at January 1, 2021	$	401,918	$	125,105	$	527,023
Increase from current period acquisition	—		15,860		15,860
Foreign currency translation	107		38		145
Balance at September 30, 2021	$	402,025	$	141,003	$	543,028

Schedule of Finite-Lived Intangible Assets

As of September 30, 2021 and December 31, 2020, the Company's intangible assets consisted of the following (in thousands):

	September 30, 2021						December 31, 2020
	Cost		Accumulated Amortization		Net		Cost		Accumulated Amortization		Net
Permits	$	186,334	$	100,553	$	85,781	$	183,766	$	95,033	$	88,733
Customer and supplier relationships	361,438		207,497		153,941		382,083		211,895		170,188
Other intangible assets	20,388		16,795		3,593		39,287		34,744		4,543
Total amortizable permits and other intangible assets	568,160		324,845		243,315		605,136		341,672		263,464
Trademarks and trade names	123,182		—		123,182		123,156		—		123,156
Total permits and other intangible assets	$	691,342	$	324,845	$	366,497	$	728,292	$	341,672	$	386,620

Summary of Indefinite-Lived Intangible Assets

As of September 30, 2021 and December 31, 2020, the Company's intangible assets consisted of the following (in thousands):

	September 30, 2021						December 31, 2020
	Cost		Accumulated Amortization		Net		Cost		Accumulated Amortization		Net
Permits	$	186,334	$	100,553	$	85,781	$	183,766	$	95,033	$	88,733
Customer and supplier relationships	361,438		207,497		153,941		382,083		211,895		170,188
Other intangible assets	20,388		16,795		3,593		39,287		34,744		4,543
Total amortizable permits and other intangible assets	568,160		324,845		243,315		605,136		341,672		263,464
Trademarks and trade names	123,182		—		123,182		123,156		—		123,156
Total permits and other intangible assets	$	691,342	$	324,845	$	366,497	$	728,292	$	341,672	$	386,620

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 September 30, 2021 was as follows (in thousands):

Years Ending December 31,	Expected Amortization
2021 (three months)	$	7,526
2022	30,002
2023	25,674
2024	24,180
2025	23,208
Thereafter	132,725
	$	243,315