Employee Stock Plans - Fair Value with Weighted Average Assumptions (Detail) (USD $)	3 Months Ended		9 Months Ended
	Jun. 27, 2014	Jun. 28, 2013	Jun. 27, 2014	Jun. 28, 2013
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	11.10%	13.60%	12.80%	16.50%
Expected dividend	0.00%	0.00%	0.00%	0.00%
Weighted average fair value at grant date	$ 14.42	$ 12.21	$ 14.20	$ 12.95
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 1 month 17 days	4 years 9 months 4 days
Risk-free interest rate		0.70%	1.20%	0.60%
Expected volatility		29.60%	24.60%	32.20%
Expected dividend		0.00%	0.00%	0.00%
Weighted average fair value at grant date		$ 18.21	$ 18.23	$ 19.73