Schedule of Income Taxes Paid (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Sep. 26, 2014	Sep. 27, 2013	Sep. 28, 2012
Income Taxes Paid Net [Line Items]
Income taxes paid	$ 140.8	$ 203.4	$ 134.6
Federal
Income Taxes Paid Net [Line Items]
Income taxes paid	66.2	119.1	77.6
State
Income Taxes Paid Net [Line Items]
Income taxes paid	7.3	14.9	9.3
Foreign
Income Taxes Paid Net [Line Items]
Income taxes paid	$ 67.3	$ 69.4	$ 47.7