Shareholders' Equity (Summary Of Stock-Based Compensation Expense, Net Of Tax) (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 03, 2015	Jul. 04, 2014	Jul. 03, 2015	Jul. 04, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	$ 12.0	$ 11.0	$ 24.5	$ 21.1
Cost Of Sales [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	1.0	0.8	1.9	1.5
Research And Development Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	2.1	1.7	4.3	3.2
Sales And Marketing Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	2.2	2.1	4.5	4.0
General and Administrative Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	6.7	6.4	13.8	12.4
Total Operating Expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	$ 11.0	$ 10.2	$ 22.6	$ 19.6