Stock Based Compensation (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 28, 2013	Sep. 29, 2012	Sep. 28, 2013	Sep. 29, 2012
Stock-based compensation expense
Stock based compensation expense	$ 177	$ (20)	$ 511	$ 277
Cost of revenues
Stock-based compensation expense
Stock based compensation expense	27	17	78	51
Research and development
Stock-based compensation expense
Stock based compensation expense	17	19	53	58
Sales and marketing
Stock-based compensation expense
Stock based compensation expense	30	29	80	84
General and administrative
Stock-based compensation expense
Stock based compensation expense	$ 103	$ (85)	$ 300	$ 84