Condensed Consolidated Statements of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 27, 2020	Jun. 29, 2019	Jun. 27, 2020	Jun. 29, 2019
Income Statement [Abstract]
Net sales	$ 869,867	$ 954,840	$ 1,725,975	$ 1,720,890
Cost of goods sold	354,437	379,475	703,605	693,827
Gross profit	515,430	575,365	1,022,370	1,027,063
Advertising expense	29,285	41,523	56,165	69,139
Selling, general and administrative expenses	132,016	128,738	269,202	255,519
Research and development expense	165,740	148,883	331,131	294,801
Total operating expense	327,041	319,144	656,498	619,459
Operating income	188,389	256,221	365,872	407,604
Other income (expense):
Interest income	10,455	13,735	22,481	27,439
Foreign currency (losses) gains	(4,493)	3,413	(19,916)	3,727
Other income	3,241	2,409	6,789	3,273
Total other income	9,203	19,557	9,354	34,439
Income before income taxes	197,592	275,778	375,226	442,043
Income tax provision	13,412	52,122	29,866	78,214
Net income	$ 184,180	$ 223,656	$ 345,360	$ 363,829
Net income per share:
Basic	$ 0.96	$ 1.18	$ 1.81	$ 1.92
Diluted	$ 0.96	$ 1.17	$ 1.80	$ 1.91
Weighted average common shares outstanding:
Basic	191,024	189,855	190,914	189,728
Diluted	191,597	190,714	191,640	190,657