Stock Plans (Allocation of Stock-Based Compensation Expense) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Schedule of stock-based compensation expense
Stock-based compensation expense	$ 1,203	$ 839
Total stock-based compensation expense	1,203	839
Cost of revenue
Schedule of stock-based compensation expense
Total stock-based compensation expense	235	206
Selling, general and administrative
Schedule of stock-based compensation expense
Total stock-based compensation expense	671	366
Research and development
Schedule of stock-based compensation expense
Total stock-based compensation expense	$ 297	$ 267