Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 27, 2014	Sep. 28, 2013	Sep. 27, 2014	Sep. 28, 2013
Statement of Comprehensive Income [Abstract]
Net income	$ 23,554	$ 20,259	$ 49,027	$ 53,656
Other comprehensive (loss) income – unrealized (loss) gain on available-for-sale marketable debt securities, net of income tax	(35)	47	(5)	2
Comprehensive income	$ 23,519	$ 20,306	$ 49,022	$ 53,658