Schedule of Equity Based Compensation Expense (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 28, 2012	Sep. 30, 2011	Sep. 28, 2012	Sep. 30, 2011
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Equity-based compensation expense before income taxes	$ 5.4	$ 6.3	$ 15.8	$ 21.9
Income tax benefit	(0.1)		(0.3)	(2.6)
Total equity-based compensation expense after income taxes	5.3	6.3	15.5	19.3
Cost of Revenue - products
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Equity-based compensation expense before income taxes	0.3	0.4	0.9	1.3
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	0.5	1.3	1.7
Research and Development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Equity-based compensation expense before income taxes	1.0	2.3	4.2	7.9
Sales And Marketing
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Equity-based compensation expense before income taxes	0.6	1.0	2.3	3.7
General and Administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Equity-based compensation expense before income taxes	$ 3.1	$ 2.1	$ 7.1	$ 7.3