Schedule of Equity Based Compensation Expense (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 29, 2012	Jul. 01, 2011	Jun. 29, 2012	Jul. 01, 2011
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Equity-based compensation expense before income taxes	$ 4.8	$ 8.0	$ 10.4	$ 15.6
Income tax benefit	(0.1)	(1.2)	(0.2)	(2.6)
Total equity-based compensation expense after income taxes	4.7	6.8	10.2	13.0
Cost Of Revenue - products
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Equity-based compensation expense before income taxes	0.2	0.5	0.6	1.0
Cost Of Revenue - services
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Equity-based compensation expense before income taxes	0.4	0.6	0.9	1.2
Research And Development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Equity-based compensation expense before income taxes	1.4	3.1	3.2	5.6
Sales And Marketing
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Equity-based compensation expense before income taxes	0.8	1.3	1.7	2.6
General And Administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Equity-based compensation expense before income taxes	$ 2.0	$ 2.5	$ 4.0	$ 5.2