Fair Value of Employee Stock Purchase Plan with Weighted Average Assumptions (Detail) (USD $)	3 Months Ended		9 Months Ended
	Jun. 28, 2013	Jun. 29, 2012	Jun. 28, 2013	Jun. 29, 2012
Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	6 months	6 months	6 months	6 months
Risk-free interest rate	0.10%	0.10%	0.10%	0.10%
Expected volatility	13.60%	18.00%	16.50%	20.60%
Expected dividend	0.00%	0.00%	0.00%	0.00%
Weighted average fair value at grant date	$ 12.21	$ 12.16	$ 12.95	$ 12.38
Employee Stock Option plans
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	4 years 9 months 7 days	4 years 6 months 18 days	4 years 9 months 4 days	4 years 7 months 21 days
Risk-free interest rate	0.70%	0.70%	0.60%	0.80%
Expected volatility	29.60%	34.30%	32.20%	36.90%
Expected dividend	0.00%	0.00%	0.00%	0.00%
Weighted average fair value at grant date	$ 18.21	$ 19.14	$ 19.73	$ 18.75