Reconciliation for Assets and Liabilities Measured and Recorded at Fair Value on Recurring Basis (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Jun. 29, 2012		Mar. 30, 2012		Dec. 31, 2011
Corporate Debt Securities
Fair Value, Assets And Liabilities Measured On Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	$ 31.6		$ 25.3		$ 19.2
Purchases	15.6	[1]	6.3	[1]	6.1	[1]
Ending balance	47.2		31.6		25.3
Contingent Consideration
Fair Value, Assets And Liabilities Measured On Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	(5.0)		(5.0)		(0.1)
Purchases	(4.1)	[1]	0	[1]	(4.9)	[1]
Ending balance	(9.1)		(5.0)		(5.0)
Option To Purchase A Company
Fair Value, Assets And Liabilities Measured On Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	1.4		1.4		1.4
Purchases	0	[1]	0	[1]	0	[1]
Ending balance	$ 1.4		$ 1.4		$ 1.4

[1] Amounts reported under "Contingent Consideration" represent additions to contingent consideration liabilities as a result of acquisitions of businesses.