Stock-Based Compensation - Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Allocated share-based compensation expense	$ 1,905	$ 2,331
Cost of Sales
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Allocated share-based compensation expense	271	233
Cost of Sales | Product
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Allocated share-based compensation expense	154	153
Cost of Sales | Service
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Allocated share-based compensation expense	117	80
Selling and Marketing Expense
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Allocated share-based compensation expense	1,523	2,134
Research and Development Expense
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Allocated share-based compensation expense	$ 382	$ 197