Stock-Based Compensation - Stock-Based Compensation Expense in Consolidated Statement of Income (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Dec. 29, 2012	Dec. 24, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 12,066	$ 8,657
Cost of revenues [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	1,834	1,107
Research and development [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	1,868	1,201
Selling and marketing [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	2,201	1,550
General and administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	5,941	4,799
Restructuring [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 222