Property, Plant, and Equipment (Tables)

3 Months Ended

Mar. 31, 2021

Property, Plant and Equipment [Abstract]

Schedule of property and equipment

Property and equipment as of the dates presented consists of the following (in thousands except years):

			December 31,				Estimated Useful Life (in years)
	March 31, 2021		2020		2019
Machinery and equipment	$	14,748	$	14,924	$	14,892	5
Computer equipment and software	836		828		876		3
Furniture and fixtures	185		189		186		7
Leasehold improvements (1)	4,959		4,970		4,954		7
Construction in progress	137		13		6
Property and equipment, gross	20,865		20,924		20,914
Less: accumulated depreciation and amortization	(19,505)		(19,600)		(19,144)
Property and equipment, net	$	1,360	$	1,324	$	1,770

(1) Leasehold improvements are amortized on a straight-line basis over the shorter of their estimated useful lives or the related remaining lease term.