Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 04, 2015	Sep. 28, 2014	Oct. 04, 2015	Sep. 28, 2014
Statement of Comprehensive Income [Abstract]
Tax effect on cash flow hedges	$ (3)	$ 4	$ (28)	$ (2)
Tax effect of unrealized gain (loss) on available-for-sale investments	(61)	(49)	(55)	133
Tax effect of foreign currency translation adjustment	$ 4	$ (441)	$ (525)	$ (501)