Pension Plans and Other Postretirement Benefits - Components of Net Periodic Benefit Costs (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 24, 2023	Jun. 25, 2022	Jun. 24, 2023	Jun. 25, 2022
Defined Benefit Plan Disclosure [Line Items]
Pension settlement charge			$ 0	$ 634
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 827	$ 559	2,480	1,678
Expected return on plan assets	(339)	(353)	(1,016)	(1,061)
Amortization of net loss (gain)	482	598	1,445	1,797
Pension settlement charge	0	634	0	634
Net periodic benefit cost	970	1,438	2,909	3,048
Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost	41	20	124	60
Amortization of prior service credits	(124)	(124)	(373)	(373)
Amortization of net loss (gain)	(194)	(181)	(581)	(543)
Net periodic benefit cost	$ (277)	$ (285)	$ (830)	$ (856)