Note 6 - Stock-Based Compensation - Stock Option Activity (Details) - Jun. 27, 2015 - USD ($) shares in Thousands, $ in Thousands	Total
Minimum [Member]
Outstanding at September 27, 2014 (in dollars per share)	$ 6.89
Granted (in dollars per share)	21.96
Granted (in dollars per share)	21.96
Exercised (in dollars per share)	6.89
Exercised (in dollars per share)	6.89
Outstanding at June 27, 2015 (in dollars per share)	7.55
Maximum [Member]
Outstanding at September 27, 2014 (in dollars per share)	20.50
Granted (in dollars per share)	21.96
Granted (in dollars per share)	21.96
Exercised (in dollars per share)	11.15
Exercised (in dollars per share)	11.15
Outstanding at June 27, 2015 (in dollars per share)	21.96
Weighted Average [Member]
Outstanding at September 27, 2014 (in dollars per share)	14.23
Granted (in dollars per share)	21.96
Granted (in dollars per share)	21.96
Exercised (in dollars per share)	9.17
Exercised (in dollars per share)	9.17
Outstanding at June 27, 2015 (in dollars per share)	14.92
Vested and anticipated to vest in the future at June 27, 2015 (in dollars per share)	14.91
Exercisable at June 27, 2015 (in dollars per share)	$ 13.35
Outstanding at September 27, 2014 (in shares)	871
Granted (in shares)	63
Exercised (in shares)	(27)
Exercised	$ 328
Outstanding at June 27, 2015 (in shares)	907
Outstanding at June 27, 2015	6 years 7 days
Outstanding at June 27, 2015	$ 4,499
Vested and anticipated to vest in the future at June 27, 2015 (in shares)	903
Vested and anticipated to vest in the future at June 27, 2015	6 years 3 days
Vested and anticipated to vest in the future at June 27, 2015	$ 4,491
Exercisable at June 27, 2015 (in shares)	633
Exercisable at June 27, 2015	4 years 317 days
Exercisable at June 27, 2015	$ 4,005