Stock Plans (Summary of Total Compensation Recognized Related to Outstanding Stock Options) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 05, 2020	Jun. 30, 2019	Jul. 05, 2020	Jun. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Arrangement, Expense	$ 9,603	$ 6,703	$ 12,653	$ 12,801
Cost of sales [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Arrangement, Expense	253	377	507	711
Research and development expenses [Member ]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Arrangement, Expense	316	333	588	624
Selling, general and administrative and other expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Arrangement, Expense	$ 9,034	$ 5,993	$ 11,558	$ 11,466