Fair Value of Employee Stock Purchase Plan with Weighted Average Assumptions (Detail) (USD $)	3 Months Ended		6 Months Ended
	Mar. 28, 2014	Mar. 29, 2013	Mar. 28, 2014	Mar. 29, 2013
Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)			6 months	6 months
Risk-free interest rate			0.10%	0.10%
Expected volatility			14.50%	19.30%
Expected dividend			0.00%	0.00%
Weighted average fair value at grant date			$ 13.98	$ 13.65
Employee Stock Option Plans
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	4 years 1 month 10 days	4 years 9 months 7 days	4 years 1 month 17 days	4 years 9 months 4 days
Risk-free interest rate	1.20%	0.80%	1.20%	0.60%
Expected volatility	24.60%	30.90%	24.60%	32.30%
Expected dividend	0.00%	0.00%	0.00%	0.00%
Weighted average fair value at grant date	$ 18.21	$ 19.56	$ 18.23	$ 19.74