Taxes on Earnings - Schedule of Income Taxes Paid (Detail) - USD ($) $ in Millions	12 Months Ended
	Sep. 27, 2019	Sep. 28, 2018	Sep. 29, 2017
Income Taxes Paid Net [Line Items]
Income taxes paid, net	$ 128.5	$ 86.0	$ 144.1
Federal
Income Taxes Paid Net [Line Items]
Income taxes paid, net	50.5	10.6	62.0
State
Income Taxes Paid Net [Line Items]
Income taxes paid, net	11.9	7.2	5.0
Foreign
Income Taxes Paid Net [Line Items]
Income taxes paid, net	$ 66.1	$ 68.2	$ 77.1