Description of Business - Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Cost of Sales
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Allocated share-based compensation expense	$ 127	$ 270	$ 491	$ 770
Cost of Sales | Product
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Allocated share-based compensation expense	39	170	234	482
Cost of Sales | Service
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Allocated share-based compensation expense	88	100	257	288
Operating Expenses
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Allocated share-based compensation expense	1,957	3,117	5,937	7,933
Selling, general and administrative
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Allocated share-based compensation expense	1,527	2,745	4,666	7,052
Research and development
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Allocated share-based compensation expense	$ 430	$ 372	$ 1,271	$ 881