Fair Value of Employee Stock Purchase Plan with Weighted Average Assumptions (Detail) (USD $)	3 Months Ended		6 Months Ended
	Mar. 29, 2013	Mar. 30, 2012	Mar. 29, 2013	Mar. 30, 2012
Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions And Weighted Average Fair Values [Line Items]
Expected term (in years)			6 months	6 months
Risk-free interest rate			0.10%	0.10%
Expected volatility			19.30%	21.90%
Expected dividend
Weighted average fair value at grant date			$ 13.65	$ 12.49
Employee Stock Option plans
Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions And Weighted Average Fair Values [Line Items]
Expected term (in years)	4 years 9 months 7 days	4 years 9 months 7 days	4 years 9 months 4 days	4 years 7 months 21 days
Risk-free interest rate	0.80%	0.80%	0.60%	0.80%
Expected volatility	30.90%	35.30%	32.30%	36.90%
Expected dividend
Weighted average fair value at grant date	$ 19.56	$ 20.19	$ 19.74	$ 18.75