Intangible Assets, net

9 Months Ended

Sep. 30, 2018

Goodwill and Intangible Assets Disclosure [Abstract]

Intangible Assets

Note 8.   Intangible Assets, net

Intangible assets consisted of the following for the periods indicated (in thousands):

	September 30, 2018
	Gross		Accumulated		Intangible
	Amount		amortization		assets, net
Patents	$	6,853		(2,884)	$	3,969
Trademarks		15		(13)		2
Total intangible assets	$	6,868	$	(2,897)	$	3,971

	December 31, 2017
	Gross		Accumulated		Intangible
	Amount		amortization		assets, net
Patents	$	6,524	$	(2,519)	$	4,005
Trademarks		14		(12)		2
Total intangible assets	$	6,538	$	(2,531)	$	4,007

For the three months ended September 30, 2018 and 2017, amortization expense for intangible assets, included in general and administrative expenses on the income statement, was each $0.1 million. For the nine months ended September 30, 2018 and 2017, amortization expense for intangible assets, included in general and administrative expenses on the income statement, was each $0.4 million.

The remaining weighted average amortization period for intangible assets is approximately 8 years.