Summary of Significant Accounting Policies (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 25, 2011	Jun. 30, 2012	Jun. 25, 2011
Classification of share-based compensation
Total share-based compensation	$ 1,251	$ 938	$ 2,295	$ 1,986
Income tax benefit
Total share-based compensation, net of tax	1,251	938	2,295	1,986
Cost of sales [Member]
Classification of share-based compensation
Total share-based compensation	125	90	230	182
Research and development [Member]
Classification of share-based compensation
Total share-based compensation	337	266	660	602
Selling, general and administrative [Member]
Classification of share-based compensation
Total share-based compensation	$ 789	$ 582	$ 1,405	$ 1,202