Intangible Assets

12 Months Ended

Dec. 31, 2017

Goodwill and Intangible Assets Disclosure [Abstract]

Intangible Assets

Intangible Assets

Intangible assets, the majority of which were acquired in the acquisition of TIW and OPT, consist of the following:

	Estimated Useful Lives	2017
		Gross Book Value		Accumulated Amortization			Foreign Currency Translation			Net Book Value
		(In thousands)
Trademarks	indefinite	$	8,416	$	—		$	56		$	8,472
Patents	15 - 30 years	5,946		(968		)	80			5,058
Customer relationships	5 - 15 years	26,503		(1,675		)	(64		)	24,764
Non-compete agreements	3 years	171		(57		)	—			114
		$	41,036	$	(2,700	)	$	72		$	38,408

	Estimated Useful Lives	2016
		Gross Book Value		Accumulated Amortization			Foreign Currency Translation		Net Book Value
		(In thousands)
Trademarks	indefinite	$	8,416	$	—		$	—	$	8,416
Patents	15 - 30 years	3,583		(294		)	—		3,289
Customer relationships	5 - 15 years	18,057		(168		)	—		17,889
		$	30,056	$	(462	)	$	—	$	29,594

At October 1, 2017, the Company performed its annual impairment test on its indefinite and definite-lived intangible assets and concluded that there had been no impairment because the estimated fair values of each of those intangible assets exceeded its carrying value. Relevant events and circumstances that could have a negative impact on intangible assets include: macroeconomic conditions; industry and market conditions, such as commodity prices; operating cost factors; overall financial performance; the impact of dispositions and acquisitions; and other entity-specific events. Further declines in commodity prices or sustained lower valuation for the Company's common stock could indicate a reduction in the estimate of the intangible assets' fair value which, in turn, could lead to an impairment of the intangible asset.

Amortization expense was $2.4 million, $0.2 million and none for 2017, 2016 and 2015, respectively. Based on the carrying value of intangible assets at December 31, 2017, amortization expense for the subsequent five years is estimated to be as follows: 2018—$2.2 million; 2019—$2.2 million; 2020—$2.1 million; 2021—$2.1 million; and 2022—$2.1 million.