Employee Stock Plans - Net Share-Based Compensation Expense (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Jun. 27, 2014	Jun. 28, 2013	Jun. 27, 2014	Jun. 28, 2013
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Share-based compensation expenses	$ 11,414	$ 10,524	$ 30,054	$ 33,915
Tax effects	(3,564)	(3,181)	(9,301)	(10,359)
Net share-based compensation expense	7,850	7,343	20,753	23,556
Cost of revenues - Product
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Share-based compensation expenses	950	1,058	2,374	3,443
Cost of revenues - Service
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Share-based compensation expenses	1,330	1,069	3,392	2,530
Research and development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Share-based compensation expenses	1,771	1,515	4,392	4,741
Selling, general and administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Share-based compensation expenses	$ 7,363	$ 6,882	$ 19,896	$ 23,201