Equity-Based Compensation (Schedule Of Equity-Based Compensation Expense) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 30, 2012	Apr. 01, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense before income taxes	$ 5.6	$ 7.6
Income tax benefit	(0.1)	(1.4)
Total equity-based compensation expense after income taxes	5.5	6.2
Cost Of Revenue - Products [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense before income taxes	0.4	0.5
Cost Of Revenue - Services [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense before income taxes	0.5	0.6
Research And Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense before income taxes	1.8	2.5
Sales And Marketing [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense before income taxes	0.9	1.3
General And Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense before income taxes	$ 2.0	$ 2.7