Property and Equipment (Tables)

12 Months Ended

Dec. 31, 2020

Property, Plant and Equipment [Abstract]

Property and equipment consist of the following (in thousands):


	December 31,
	2020		2019
Leasehold improvements	$	6,010	$	5,321
Laboratory and clean room equipment	15,524		14,894
Furniture and office equipment	15,295		15,118
Construction in progress	3,321		972
Asset retirement cost	785		—
Property and equipment, gross	40,935		36,305
Less accumulated depreciation and amortization	(29,498)		(23,977)
Property and equipment, net of accumulated depreciation	$	11,437	$	12,328

Schedule of depreciation

Depreciation expense for each of the years ended December 31, 2020, 2019, and 2018 was recorded in certain captions of the consolidated statements of operations for those periods in the amounts shown in the table below (in thousands):


	Year ended December 31,
	2020		2019		2018
Cost of sales	$	2,022	$	1,965	$	1,757
Selling, general and administrative expenses	3,416		4,223		3,760
Research and development expenses	344		358		365
Total	$	5,782	$	6,546	$	5,882