Pension Plans and Other Postretirement Benefits - Components of Net Periodic Benefit Costs (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 25, 2023	Mar. 26, 2022	Mar. 25, 2023	Mar. 26, 2022
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 826	$ 560	$ 1,653	$ 1,119
Expected return on plan assets	(338)	(354)	(677)	(708)
Amortization of net loss (gain)	481	600	963	1,199
Net periodic benefit cost	969	806	1,939	1,610
Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost	42	20	83	40
Amortization of prior service credits	(125)	(125)	(249)	(249)
Amortization of net loss (gain)	(193)	(181)	(387)	(362)
Net periodic benefit cost	$ (276)	$ (286)	$ (553)	$ (571)