Note 10 - Income Taxes - Income Tax Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 30, 2017
Provision for income taxes at federal statutory rate	$ 1,566	$ 10,444	$ 11,959
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	24.50%	35.00%
State income taxes, net of federal tax benefit	$ 297	$ 739	$ 598
State income taxes, net of federal tax benefit	4.00%	1.70%	1.80%
Stock-based compensation	$ 90	$ (634)
Stock-based compensation	1.20%	(1.50%)
Valuation allowance	$ 24	$ (18)	$ (29)
Valuation allowance	0.30%	0.00%	(0.10%)
Federal tax return true-up	$ (142)	$ (147)
Federal tax return true-up	(1.90%)	(0.30%)
Change in federal tax rate - Tax Cuts and Jobs Act		$ (3,307)
Change in federal tax rate - Tax Cuts and Jobs Act		(7.80%)
Qualified production activities deduction		$ (832)	$ (768)
Qualified production activities deduction		(2.00%)	(2.20%)
Other, net	$ 22	$ 119	$ (140)
Other, net	0.30%	0.30%	(0.50%)
Provision for income taxes	$ 1,857	$ 6,364	$ 11,620
Provision for income taxes	24.90%	14.90%	34.00%