Note 8 - Postretirement and Postemployment Benefits - Benefit Obligations and Plan Assets (Details) - Other Postretirement Benefits Plan [Member] - USD ($) $ in Thousands	12 Months Ended
	Sep. 27, 2020	Sep. 29, 2019
Benefit obligation, beginning of year	$ 11,752	$ 11,756
Business combination	36,800	0
Service cost	500	0
Interest cost	869	412
Actuarial loss (gain)	(982)	1,033
Benefits paid, net of premiums received	(1,374)	(1,507)
Medicare Part D subsidies	72	58
Benefit obligation, end of year	47,637	11,752
Fair value of plan assets, beginning of year:	24,135	24,647
Business combination	0	0
Actual return on plan assets	1,594	2,097
Employer contributions	646	222
Benefits paid, net of premiums and Medicare Part D subsidies received	(1,077)	(1,449)
Benefits paid for active employees	(438)	(1,382)
One time asset transfer	846
Fair value of plan assets, end of year	25,706	24,135
Funded status	$ (21,931)	$ 12,383