Consolidated Statements of Other Comprehensive Income (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Apr. 01, 2012	Apr. 03, 2011
Statement of Income and Comprehensive Income [Abstract]
Net income	$ 14,282	$ 13,636
Other comprehensive income, net of tax:
Net unrealized gain (loss) on available-for-sale investments, net of tax of $291 and ($53) in 2012 and 2011, respectively	1,220	(558)
Foreign currency translation adjustment, net of tax of $206 and $327 in 2012 and 2011, respectively	5,326	9,604
Other comprehensive income	6,546	9,046
Comprehensive income	$ 20,828	$ 22,682