Note 6 - Share-based Compensation and Post-retirement Benefits - Summary of Share-based Compensation Expense (Benefit) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 25, 2023	Mar. 26, 2022	Mar. 25, 2023	Mar. 26, 2022
Employee share-based compensation	$ 1,147	$ 921	$ 2,247	$ 1,917
The above compensation is net of tax benefits	166	346	305	433
Share-Based Payment Arrangement, Option [Member]
Employee share-based compensation	559	586	1,179	1,400
Stock Purchase Plan [Member]
Employee share-based compensation	197	90	424	150
Stock Issued to Outside Directors [Member]
Employee share-based compensation	27	11	27	22
Restricted Stock Units (RSUs) [Member]
Employee share-based compensation	193	152	374	224
Performance Shares [Member]
Employee share-based compensation	$ 171	$ 82	$ 243	$ 121