Note 8 - Pension Plans - Assumptions (Details)	12 Months Ended
	Sep. 26, 2021	Sep. 27, 2020	Sep. 29, 2019
Interest crediting rate	2.50%	2.50%
Pension Plan [Member]
Discount rate	2.70%	2.80%
Discount rate - service cost	3.00%	3.30%	4.20%
Discount rate - interest cost	1.90%	2.60%	3.90%
Expected long-term return on plan assets	5.90%	6.00%	5.50%