GOODWILL AND OTHER INTANGIBLE ASSETS (Tables)

12 Months Ended

Dec. 31, 2019

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Changes to Goodwill

The changes in goodwill for the years ended December 31, 2019 and 2018 were as follows (in thousands):

	Environmental Services			Safety-Kleen			Totals
Balance at January 1, 2018	$	172,386		$	306,137		$	478,523
Increase from current period acquisitions	37,007			3,697			40,704
Measurement period adjustments from prior period acquisitions	(78		)	—			(78		)
Decrease from disposition of business	—			—			—
Foreign currency translation	(2,296		)	(2,664		)	(4,960		)
Balance at December 31, 2018	$	207,019		$	307,170		$	514,189
Increase from current period acquisitions	7,378			5,225			12,603
Measurement period adjustments from prior period acquisitions	(2,675		)	(1,355		)	(4,030		)
Foreign currency translation	809			1,442			2,251
Balance at December 31, 2019	$	212,531		$	312,482		$	525,013

Schedule of Finite-Lived Intangible Assets by Major Class

As of December 31, 2019 and 2018, the Company's finite-lived and indefinite-lived intangible assets consisted of the following (in thousands):

	December 31, 2019						December 31, 2018
	Cost		Accumulated Amortization		Net		Cost		Accumulated Amortization		Net
Permits	$	184,235	$	87,228	$	97,007	$	177,583	$	79,358	$	98,225
Customer and supplier relationships	401,696		207,884		193,812		393,487		179,824		213,663
Other intangible assets	38,331		33,018		5,313		37,262		29,743		7,519
Total amortizable permits and other intangible assets	624,262		328,130		296,132		608,332		288,925		319,407
Trademarks and trade names	122,934		—		122,934		122,468		—		122,468
Total permits and other intangible assets	$	747,196	$	328,130	$	419,066	$	730,800	$	288,925	$	441,875

Schedule of Indefinite-Lived Intangible Assets

As of December 31, 2019 and 2018, the Company's finite-lived and indefinite-lived intangible assets consisted of the following (in thousands):

	December 31, 2019						December 31, 2018
	Cost		Accumulated Amortization		Net		Cost		Accumulated Amortization		Net
Permits	$	184,235	$	87,228	$	97,007	$	177,583	$	79,358	$	98,225
Customer and supplier relationships	401,696		207,884		193,812		393,487		179,824		213,663
Other intangible assets	38,331		33,018		5,313		37,262		29,743		7,519
Total amortizable permits and other intangible assets	624,262		328,130		296,132		608,332		288,925		319,407
Trademarks and trade names	122,934		—		122,934		122,468		—		122,468
Total permits and other intangible assets	$	747,196	$	328,130	$	419,066	$	730,800	$	288,925	$	441,875

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 December 31, 2019 is as follows (in thousands):

Years ending December 31,	Expected Amortization
2020	$	33,083
2021	29,788
2022	29,534
2023	25,306
2024	23,921
Thereafter	154,500
	$	296,132