Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 02, 2017	Jul. 03, 2016	Jul. 02, 2017	Jul. 03, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 56,072	$ 42,759	$ 101,727	$ 57,644
Cash flow hedges:
Net unrealized gain (loss), net of tax of $7 and ($15) in the three-month periods and net of tax of $3 and ($97) in the six-month periods, respectively	59	(302)	(12)	(879)
Reclassification of net realized (gain) loss into current operations	(9)	190	35	186
Net change related to cash flow hedges	50	(112)	23	(693)
Available-for-sale investments:
Net unrealized gain (loss), net of tax of $58 and $243 in the three-month periods and net of tax of $150 and $510 in the six-month periods, respectively	307	1,351	818	2,632
Reclassification of net realized (gain) loss into current operations	(42)	(141)	(107)	(128)
Net change related to available-for-sale investments	265	1,210	711	2,504
Foreign currency translation adjustments:
Foreign currency translation adjustments, net of tax of $0 and ($155) in the three-month periods and net of tax of $0 and $174 in the six-month periods, respectively	10,263	(2,546)	12,744	2,614
Other comprehensive income (loss), net of tax	10,578	(1,448)	13,478	4,425
Total comprehensive income	$ 66,650	$ 41,311	$ 115,205	$ 62,069