Stock-Based Compensation - Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Stock-based compensation expense
Stock-based compensation expense (in dollars)	$ 939	$ 223	$ 7,776	$ 481
Cost of revenue - product
Stock-based compensation expense
Stock-based compensation expense (in dollars)	138	27	359	85
Cost of revenue - service
Stock-based compensation expense
Stock-based compensation expense (in dollars)	91	7	203	21
Research and development
Stock-based compensation expense
Stock-based compensation expense (in dollars)	195	9	515	30
Sales and marketing
Stock-based compensation expense
Stock-based compensation expense (in dollars)	158	21	440	65
General and administrative
Stock-based compensation expense
Stock-based compensation expense (in dollars)	$ 357	$ 159	$ 6,259	$ 280