Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 28, 2013	Sep. 29, 2012	Sep. 28, 2013	Sep. 29, 2012
Statement of Comprehensive Income [Abstract]
Net income	$ 20,259	$ 26,209	$ 53,656	$ 65,599
Other comprehensive income (loss) – unrealized gain (loss) on available-for-sale marketable debt securities, net of income tax	47	32	2	(6)
Comprehensive income	$ 20,306	$ 26,241	$ 53,658	$ 65,593