Note 5 - Summary of Share-based Compensation Expense (Benefit) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 30, 2019	Mar. 31, 2018	Mar. 30, 2019	Mar. 31, 2018
Share-based compensation expense	$ 550	$ 570	$ 1,248	$ 1,386
The above compensation is net of tax benefits	410	344	683	482
Share-based Payment Arrangement, Option [Member]
Share-based compensation expense	449	471	1,078	1,086
Stock Purchase Plan [Member]
Share-based compensation expense	68	66	137	266
Director Stock Award [Member]
Share-based compensation expense	33	32	33	32
Restricted Stock [Member]
Share-based compensation expense		$ 1		$ 2