Note 6 - Pension, Postretirement and Postemployment Defined Benefit Plans - Net Periodic Cost (Benefit) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 26, 2022	Jun. 27, 2021	Jun. 26, 2022	Jun. 27, 2021
Amortization of prior service benefit	$ 212	$ 0	$ 424	$ (1)
Amortization of prior service benefit	212	0	424	(1)
Pension Plan [Member]
Service cost for benefits earned during the period	287	633	1,030	1,899
Interest cost on projected benefit obligation	2,001	1,787	5,939	5,361
Expected return on plan assets	(4,535)	(4,672)	(13,606)	(14,016)
Amortization of net loss	(687)	1,004	(2,633)	3,013
Curtailment gain	0	0	(1,027)	0
Pension benefit	(2,722)	(1,248)	(9,873)	(3,744)
Postretirement Health Coverage [Member]
Service cost for benefits earned during the period	27	240	81	690
Interest cost on projected benefit obligation	85	239	255	601
Expected return on plan assets	(263)	(252)	(789)	(756)
Amortization of net loss	(249)	(172)	(747)	(516)
Amortization of prior service benefit	(162)	(162)	(486)	(485)
Curtailment gain	0	0	0	(23,830)
Pension benefit	(562)	(107)	(1,686)	(24,296)
Amortization of prior service benefit	$ (162)	$ (162)	$ (486)	$ (485)