Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 05, 2015	Jun. 29, 2014	Jul. 05, 2015	Jun. 29, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 43,714	$ 25,948	$ 64,216	$ 44,454
Cash flow hedges:
Change in net unrealized gain (loss), net of tax of $48 and $10 in the three-month periods and net of tax of $(25) and ($6) in the six-month periods, respectively	237	(36)	(283)	(235)
Reclassification of net realized loss into current operations	69	24	179	57
Net change related to cash flow hedges	306	(12)	(104)	(178)
Available-for-sale investments:
Change in net unrealized gain (loss), net of tax of ($128) and $69 in the three-month periods and net of tax of $6 and $182 in the six-month periods, respectively	(333)	542	566	1,561
Reclassification of net realized gain into current operations	(192)	(105)	(221)	(606)
Net change related to available-for-sale investments	(525)	437	345	955
Foreign currency translation adjustments:
Change in currency translation adjustments, net of tax of $107 and $53 in the three-month periods and net of tax of ($529) and $60 in the six-month periods, respectively	2,450	(544)	(8,240)	(99)
Other comprehensive income (loss), net of tax	2,231	(119)	(7,999)	678
Total comprehensive income	$ 45,945	$ 25,829	$ 56,217	$ 45,132