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Note 6 - Stock-based Compensation (Details Textual) - USD ($)		3 Months Ended		6 Months Ended
	Feb. 28, 2020	Apr. 01, 2023	Apr. 02, 2022	Apr. 01, 2023	Apr. 02, 2022
Share-Based Payment Arrangement, Option [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period				3 years
Share-Based Compensation Arrangement by Share-Based Payment Award, Expiration Period				10 years
Share-Based Payment Arrangement, Expense		$ 439,000	$ 374,000	$ 475,000	$ 480,000
Share-Based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount		650,000		$ 650,000
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition				2 years 10 days
Restricted Stock Units (RSUs) [Member]
Share-Based Payment Arrangement, Expense		544,000	$ 455,000	$ 638,000	$ 622,000
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition				1 year 6 months 21 days
Share-Based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount		$ 1,200,000		$ 1,200,000
Restricted Stock Units (RSUs) [Member] \| Director [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period				1 year
Restricted Stock Units (RSUs) [Member] \| Employees [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period				3 years
The 2015 Equity Incentive Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Additional Shares Authorized	750,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant		500,000		500,000