Other Intangible Assets

The following is a summary of the Company’s other intangible assets as of December 31 (in thousands):



	2018			2017			Weighted Average Life
Customer lists	$	73,792		$	74,615		14.4
Non-competition agreements	950			964			4.1
Trade names	2,510			2,510			13.3
Patents	57			57			9.0
	77,309			78,146
Less accumulated amortization and impairment	(67,481		)	(50,583		)
Intangible assets, net	$	9,828		$	27,563

In accordance with ASC 350, Intangibles – Goodwill and Other, the Company amortizes its intangible assets with finite lives over their respective estimated useful lives and reviews for impairment whenever impairment indicators exist. Impairment indicators could include significant under-performance relative to the historical or projected future operating results, significant changes in the manner of use of assets, significant negative industry or economic trends or significant changes in the Company’s market capitalization relative to net book value. Any changes in key assumptions used by the Company, including those set forth above, could result in an impairment charge and such a charge could have a material adverse effect on the Company’s consolidated results of operations. The Company’s intangible assets consist of customer lists, non-competition agreements, trade names and patents. The Company’s customer lists, which have an estimated weighted-average useful life of approximately fourteen years, are being amortized using the economic life method. The Company’s non-competition agreements, trade names, and patents are being amortized on a straight-line basis over their estimated weighted-average useful lives of approximately four years, thirteen years, and nine years, respectively.

Amortization expense related to these intangible assets was $3.6 million, $5.0 million, and $5.5 million for the years ended December 31, 2018, 2017, and 2016, respectively. The Company's customer lists had accumulated amortization and impairment of $64.5 million and $47.8 million as of December 31, 2018 and 2017, respectively. The Company's trade names had accumulated amortization and impairment of $2.0 million and $1.8 million as of December 31, 2018 and 2017, respectively. The Company's patents and non-competition agreements were fully amortized as of December 31, 2018 and 2017.

The estimated amortization expense for the next five years and thereafter, is as follows (in thousands):



2019	$	2,122
2020	2,021
2021	1,783
2022	1,407
2023	961
Thereafter	1,534
	$	9,828

2018 Intangible Assets Impairment

In the third quarter of 2018, the Company changed its reporting units as part of a segment change, which required an interim impairment assessment. The Company's intangible and long-lived assets associated with the reporting units assessed were also reviewed for impairment. It was determined that the fair value of intangible assets in EMEA and LATAM was less than the recorded book value of certain customer lists.

As a result, the Company recognized a $13.8 million non-cash, intangible asset impairment charge related to certain customer lists, which is included in the accumulated amortization balance above. Of the total charge, $0.6 million related to the LATAM reportable segment, and $13.2 million related to the EMEA reportable segment.

2016 Intangible Assets Impairment

During the fourth quarter of 2016, the Company recorded a non-cash, intangible asset impairment charge of $0.1 million related to a trade name acquired in a prior year business combination in the EMEA reportable segment. The charge is included in the depreciation and amortization line item of the income statement.