Property and Equipment (Detail) - USD ($) $ in Millions	12 Months Ended
	Sep. 27, 2015	Sep. 28, 2014	Sep. 29, 2013
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 536.0	$ 436.8
Accumulated depreciation	(393.8)	(303.8)
Land	1.9	2.1
Construction in progress	8.6	13.6
Property and equipment, net	$ 152.7	148.7	$ 125.2
Property plant and equipment useful life	Shorter of asset life or life of lease
Depreciation expense	$ 36.2	32.9	$ 28.8
Buildings
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	43.0	40.1
Machinery and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	429.1	339.8
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	9.8	9.9
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 54.1	$ 47.0
Property plant and equipment useful life	Shorter of asset life or life of lease
Minimum | Buildings
Property, Plant and Equipment [Line Items]
Property plant and equipment useful life	20 years
Minimum | Machinery and equipment
Property, Plant and Equipment [Line Items]
Property plant and equipment useful life	3 years
Minimum | Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property plant and equipment useful life	5 years
Maximum | Buildings
Property, Plant and Equipment [Line Items]
Property plant and equipment useful life	40 years
Maximum | Machinery and equipment
Property, Plant and Equipment [Line Items]
Property plant and equipment useful life	10 years
Maximum | Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property plant and equipment useful life	10 years