Intangible Assets (Tables)

9 Months Ended

Sep. 30, 2020

Intangible Assets, Net (Excluding Goodwill) [Abstract]

Schedule of Intangible Assets

Intangible assets consisted of the following: 

	September 30, 2020							December 31, 2019
(In thousands)	Gross Carrying Amount		Accumulated Amortization			Net		Gross Carrying Amount		Accumulated Amortization			Net
Patents	$	3,014	$	(2,772	)	$	242	$	2,898	$	(2,662	)	$	236
Software	206		(193		)	13		206		(170		)	36
Marketing assets and customer relationships	101		(70		)	31		101		(63		)	38
Total intangible assets	$	3,321	$	(3,035	)	$	286	$	3,205	$	(2,895	)	$	310

Schedule of Amortization Expense For Intangible Assets

Amortization expense in the three and nine months ended September 30, 2020 and the three and nine months ended September 30, 2019 was as follows:  

	Three Months Ended September 30,				Nine Months Ended September 30,
(In thousands)	2020		2019		2020		2019
Patents	$	38	$	33	$	111	$	97
Software		7		7		22		22
Marketing assets and customer relationships		2		3		7		7
Total amortization expense	$	47	$	43	$	140	$	126