Segment Information - Long Lived Assets by Geographic Area (Detail) - USD ($) $ in Millions	Oct. 01, 2017	Oct. 02, 2016	Sep. 27, 2015
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	$ 197.6	$ 174.9	$ 152.7
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	138.9	119.2	117.6
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	18.3	16.4	13.9
Asia
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	23.1	22.6	18.9
Other Geographic Area [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	$ 17.3	$ 16.7	$ 2.3