GOODWILL AND OTHER INTANGIBLE ASSETS

9 Months Ended

Sep. 30, 2019

Goodwill and Intangible Assets Disclosure [Abstract]

The changes in goodwill by segment for the nine months ended September 30, 2019 were as follows (in thousands):



	Environmental Services			Safety-Kleen			Totals
Balance at January 1, 2019	$	207,019		$	307,170		$	514,189
Increase from current period acquisitions	7,514			5,225			12,739
Measurement period adjustments from prior period acquisitions	(2,675		)	(1,355		)	(4,030		)
Foreign currency translation	780			903			1,683
Balance at September 30, 2019	$	212,638		$	311,943		$	524,581

The Company assesses goodwill for impairment on an annual basis as of December 31 or at an interim date when events or changes in the business environment would more likely than not reduce the fair value of a reporting unit below its carrying value.

As of September 30, 2019 and December 31, 2018, the Company's total intangible assets consisted of the following (in thousands):



	September 30, 2019						December 31, 2018
	Cost		Accumulated Amortization		Net		Cost		Accumulated Amortization		Net
Permits	$	182,667	$	84,899	$	97,768	$	177,583	$	79,358	$	98,225
Customer and supplier relationships	400,498		200,766		199,732		393,487		179,824		213,663
Other intangible assets	37,932		32,329		5,603		37,262		29,743		7,519
Total amortizable permits and other intangible assets	621,097		317,994		303,103		608,332		288,925		319,407
Trademarks and trade names	122,760		—		122,760		122,468		—		122,468
Total permits and other intangible assets	$	743,857	$	317,994	$	425,863	$	730,800	$	288,925	$	441,875

Amortization expense of permits and other intangible assets was $8.4 million and $26.6 million in the three and nine months ended September 30, 2019, respectively. Amortization expense of permits and other intangible assets was $8.1 million and $26.0 million in the three and nine months ended September 30, 2018, respectively.

The expected amortization of the net carrying amount of finite-lived intangible assets at September 30, 2019 was as follows (in thousands):



Years Ending December 31,	Expected Amortization
2019 (three months)	$	8,305
2020	31,942
2021	28,667
2022	28,406
2023	24,193
Thereafter	181,590
	$	303,103