Commitments and Contingencies - Accrued Product Warranty (Detail) - USD ($) $ in Millions	9 Months Ended
	Jul. 03, 2015	Jun. 27, 2014
Movement in Standard and Extended Product Warranty, Increase (Decrease) [Roll Forward]
Accrued product warranty, at beginning of period	$ 49.3	$ 53.2
Charged to cost of revenues	33.1	38.8
Actual product warranty expenditures	(38.8)	(41.5)
Accrued product warranty, at end of period	$ 43.6	$ 50.5