Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2020

Share-based Payment Arrangement [Abstract]

Schedule of non-cash stock-based compensation expense

Non-cash stock-based compensation expense (employee stock purchase plan, service-based stock options and restricted stock units) included in cost of goods sold, research and development expenses and selling, general and administrative expenses is summarized in the following table: 

	Three Months Ended March 31,
(in thousands)	2020		2019
Cost of goods sold	$	493	$	260
Research and development	513		525
General, selling and administrative	2,762		1,843
Total non-cash stock-based compensation expense	$	3,768	$	2,628