Note 5 - Stock-Based Compensation (Detail) - Stock Option Activity (USD $) In Thousands, except Per Share data, unless otherwise specified	6 Months Ended
	Mar. 30, 2013
Outstanding at September 29, 2012 (in Shares)	1,160
Outstanding at March 30, 2013 (in Shares)	971
Outstanding at March 30, 2013 (in Dollars)	$ 4,446
Outstanding at March 30, 2013	6 years 277 days
Vested and anticipated to vest in the future at March 30, 2013 (in Shares)	965
Vested and anticipated to vest in the future at March 30, 2013	6 years 9 months
Vested and anticipated to vest in the future at March 30, 2013 (in Dollars)	4,422
Exercisable at March 30, 2013 (in Shares)	632
Exercisable at March 30, 2013	5 years 222 days
Exercisable at March 30, 2013 (in Dollars)	2,970
Granted (in Shares)	65
Exercised (in Shares)	(254)
Exercised (in Dollars)	$ 1,799
Minimum [Member]
Outstanding at September 29, 2012	$ 0.36
Outstanding at March 30, 2013	$ 5.43
Granted	$ 16.45
Exercised	$ 0.36
Maximum [Member]
Outstanding at September 29, 2012	$ 20.27
Outstanding at March 30, 2013	$ 20.27
Granted	$ 16.45
Exercised	$ 12.43
Weighted Average [Member]
Outstanding at September 29, 2012	$ 11.09
Outstanding at March 30, 2013	$ 12.02
Vested and anticipated to vest in the future at March 30, 2013	$ 12.01
Exercisable at March 30, 2013	$ 12.03
Granted	$ 16.45
Exercised	$ 8.89