Reconciliation for Assets and Liabilities Measured and Recorded at Fair Value on Recurring Basis (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Dec. 27, 2013
Corporate Debt Security
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning balance	$ 62.7
Additions, including accrued interest	11.3
Settlements	0	[1]
Ending balance	74.0
Option to Purchase a Company
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning balance	1.4
Additions, including accrued interest	0
Settlements	0	[1]
Ending balance	1.4
Contingent Consideration
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning balance	(2.5)
Additions, including accrued interest	0
Settlements	0.2	[1]
Ending balance	$ (2.3)

[1] Amounts reported under “Contingent Consideration” represent cash payments to settle contingent consideration liabilities.