Stock-Based Compensation - Schedule of Stock Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share-based compensation expense	$ 874	$ 853
Cost of product sales
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share-based compensation expense	41	71
Cost of service sales
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share-based compensation expense	0	0
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share-based compensation expense	172	170
Sales, marketing and support
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share-based compensation expense	182	181
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share-based compensation expense	$ 479	$ 431