Stock-Based Compensation (Details 5) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 28, 2013	Dec. 29, 2012	Dec. 31, 2011
Stock-based compensation expense for all share-based payment awards
Total stock-based compensation expense related to employee stock options and employee stock purchases	$ 7,674	$ 5,890	$ 4,473
Cost of products [Member]
Stock-based compensation expense for all share-based payment awards
Total stock-based compensation expense related to employee stock options and employee stock purchases	207	164	176
Cost of service [Member]
Stock-based compensation expense for all share-based payment awards
Total stock-based compensation expense related to employee stock options and employee stock purchases	278	230	218
Research and development [Member]
Stock-based compensation expense for all share-based payment awards
Total stock-based compensation expense related to employee stock options and employee stock purchases	1,478	1,220	984
Selling [Member]
Stock-based compensation expense for all share-based payment awards
Total stock-based compensation expense related to employee stock options and employee stock purchases	1,894	1,791	1,366
General and administrative [Member]
Stock-based compensation expense for all share-based payment awards
Total stock-based compensation expense related to employee stock options and employee stock purchases	2,919	2,485	1,729
Restructuring [Member]
Stock-based compensation expense for all share-based payment awards
Total stock-based compensation expense related to employee stock options and employee stock purchases	$ 898	$ 0	$ 0