Stock-Based Compensation - Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Stock-based compensation expense
Stock-based compensation expense (in dollars)	$ 4,250	$ 565	$ 254
Cost of revenue - product
Stock-based compensation expense
Stock-based compensation expense (in dollars)	191	102	57
Cost of revenue - service
Stock-based compensation expense
Stock-based compensation expense (in dollars)	46	23	3
Research and development
Stock-based compensation expense
Stock-based compensation expense (in dollars)	62	25	9
Selling and marketing
Stock-based compensation expense
Stock-based compensation expense (in dollars)	138	91	57
General and administrative
Stock-based compensation expense
Stock-based compensation expense (in dollars)	$ 3,813	$ 324	$ 128