CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 28, 2014	Jun. 29, 2013	Jun. 28, 2014	Jun. 29, 2013
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 27,557	$ 30,566	$ 69,163	$ 54,108
Other comprehensive income (loss):
Unrealized gains (losses) on hedging transactions, net of income taxes	776	(391)	1,389	1,352
Unrealized holding gains (losses) on investments, net of income taxes	348	(867)	496	(939)
Foreign currency translation adjustment	(29)	223	(196)	317
Comprehensive income	$ 28,652	$ 29,531	$ 70,852	$ 54,838