Taxes on Earnings - Schedule of Income Taxes Paid (Detail) - USD ($) $ in Millions	12 Months Ended
	Sep. 28, 2018	Sep. 29, 2017	Sep. 30, 2016
Income Taxes Paid Net [Line Items]
Income taxes paid, net	$ 86.0	$ 144.1	$ 155.9
Federal
Income Taxes Paid Net [Line Items]
Income taxes paid, net	10.6	62.0	78.3
State
Income Taxes Paid Net [Line Items]
Income taxes paid, net	7.2	5.0	5.0
Foreign
Income Taxes Paid Net [Line Items]
Income taxes paid, net	$ 68.2	$ 77.1	$ 72.6