Business Segments and Geographic Information - Revenues by Geography (Detail)	12 Months Ended
	Sep. 27, 2014	Sep. 28, 2013	Sep. 29, 2012
Schedule Of Geographical Segments [Line Items]
Revenues	100.00%	100.00%	100.00%
United States [Member]
Schedule Of Geographical Segments [Line Items]
Revenues	75.00%	75.00%	74.00%
Europe [Member]
Schedule Of Geographical Segments [Line Items]
Revenues	13.00%	13.00%	12.00%
Asia-Pacific [Member]
Schedule Of Geographical Segments [Line Items]
Revenues	8.00%	8.00%	8.00%
All Others [Member]
Schedule Of Geographical Segments [Line Items]
Revenues	4.00%	4.00%	6.00%