Property and Equipment (Detail) - USD ($) $ in Millions	12 Months Ended
	Oct. 02, 2016	Sep. 27, 2015	Sep. 28, 2014
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 548.0	$ 536.0
Accumulated depreciation	(382.2)	(393.8)
Land	1.5	1.9
Construction in progress	7.6	8.6
Property and equipment, net	$ 174.9	152.7	$ 148.7
Property plant and equipment useful life	Shorter of asset life or life of lease
Depreciation expense	$ 46.1	36.2	$ 32.9
Buildings
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	37.2	43.0
Machinery and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	439.3	429.1
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	8.9	9.8
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 62.6	$ 54.1
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