Schedule of Fair Values of Plan Assets (Detail) (USD $) In Millions, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012
Defined Benefit Plan Disclosure [Line Items]
Plan assets	$ 180.8	$ 142.6
Mutual Funds Equities
Defined Benefit Plan Disclosure [Line Items]
Plan assets	49.9	40.3
Mutual Funds Debt
Defined Benefit Plan Disclosure [Line Items]
Plan assets	26.1	23.2
Mutual Funds Real Estate
Defined Benefit Plan Disclosure [Line Items]
Plan assets	3.6	3.5
Insurance Contracts
Defined Benefit Plan Disclosure [Line Items]
Plan assets	86.3	73.3
Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Plan assets	14.9	2.3
Quoted Prices in Active Markets for Identical Instruments (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Plan assets	14.9	2.3
Quoted Prices in Active Markets for Identical Instruments (Level 1) | Mutual Funds Equities
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Quoted Prices in Active Markets for Identical Instruments (Level 1) | Mutual Funds Debt
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Quoted Prices in Active Markets for Identical Instruments (Level 1) | Mutual Funds Real Estate
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Quoted Prices in Active Markets for Identical Instruments (Level 1) | Insurance Contracts
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Quoted Prices in Active Markets for Identical Instruments (Level 1) | Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Plan assets	14.9	2.3
Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Plan assets	165.9	140.3
Significant Other Observable Inputs (Level 2) | Mutual Funds Equities
Defined Benefit Plan Disclosure [Line Items]
Plan assets	49.9	40.3
Significant Other Observable Inputs (Level 2) | Mutual Funds Debt
Defined Benefit Plan Disclosure [Line Items]
Plan assets	26.1	23.2
Significant Other Observable Inputs (Level 2) | Mutual Funds Real Estate
Defined Benefit Plan Disclosure [Line Items]
Plan assets	3.6	3.5
Significant Other Observable Inputs (Level 2) | Insurance Contracts
Defined Benefit Plan Disclosure [Line Items]
Plan assets	86.3	73.3
Significant Other Observable Inputs (Level 2) | Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Significant Unobservable Inputs (Level 3) | Mutual Funds Equities
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Significant Unobservable Inputs (Level 3) | Mutual Funds Debt
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Significant Unobservable Inputs (Level 3) | Mutual Funds Real Estate
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Significant Unobservable Inputs (Level 3) | Insurance Contracts
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Significant Unobservable Inputs (Level 3) | Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Plan assets	$ 0	$ 0