Note 8 - Pension Plans - The Activity Within Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 26, 2021	Sep. 27, 2020	Sep. 29, 2019
Change in unrecognized benefit plan gain (loss) arising during the period, net of taxes $19,148, $4,095, and $7,137, respectively	$ 59,663	$ 10,329	$ (16,880)
Amortization of items to periodic pension and other post-employment benefit costs during the period, net of taxes $819, $542, and $162, respectively	2,574	(1,265)	(488)
Other comprehensive income (loss) recognized in operations, net of taxes	$ 62,237	$ 9,064	$ (17,368)