Taxes on Earnings - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Sep. 28, 2018	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Income Tax [Line Items]
Increase (decrease) in valuation allowance	$ (4.2)	$ 26.2	$ 9.9
Unrecognized tax benefits	43.5	42.7	$ 40.7	$ 39.5
Amount that would affect the effective tax rate	34.0
Accrued interest and penalties related to unrecognized tax benefits	6.6	8.9
Net expense (benefit) related to interest and penalties was included in taxes on earnings	(1.8)	$ 0.9
Foreign Tax Authority
Income Tax [Line Items]
Net operating loss carry forwards	416.0
Amount unavailable to the company under local loss utilization	20.7
Internal Revenue Service (IRS)
Income Tax [Line Items]
Net operating loss carry forwards	8.9
Federal
Income Tax [Line Items]
Net operating loss carryforwards subject to an annual limitation	0.8
State and Local Jurisdiction
Income Tax [Line Items]
Net operating loss carry forwards	$ 6.3