Intangibles (Tables)

12 Months Ended

Dec. 31, 2018

Goodwill And Intangible Assets Disclosure [Abstract]

Amortization of Intangible Assets Acquired

Amortization of intangible assets acquired is calculated using the straight-line method over the estimated useful lives of the assets.

	Estimated Life	December 31,			December 31,
	(years)	2018			2017
Capitalized patent costs	17-20	$	8,757		$	7,978
Intangible assets acquired:
Purchased patents and intellectual property	3-10		250			250
Existing technology	5		1,560			1,560
Customer relationships	7		290			290
Backlog	2		760			760
Tradenames	3		290			290
Non-solicitation agreements	1		120			120
Gross intangible assets			12,027			11,248
Accumulated amortization			(5,378	)		(4,867	)
Intangibles, net		$	6,649		$	6,381

Amortization Expense on Intangible Assets

Amortization expense on intangible assets was as follows:   

	Year Ended		Year Ended
	December 31,		December 31,
	2018		2017
Amortization expense	$	516	$	741

Estimated Future Aggregate Amortization Expense

For intangible assets recorded at December 31, 2018, the estimated future aggregate amortization expense for the years ending December 31, 2019 through December 31, 2023 is approximately as follows:

	Amortization
Year ending December 31:	Expense
2019	$	502
2020		443
2021		380
2022		364
2023		352