Pension, Postretirement and Postemployment Defined Benefit Plans - Net Periodic Cost (Benefit) (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 24, 2023	Dec. 25, 2022
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost for benefits earned during the period	$ 1	$ 5
Interest cost on projected benefit obligation	2,515	2,592
Expected return on plan assets	(2,453)	(2,548)
Amortization of net gain (loss)	(2)	2
Amortization of prior service benefit	212	213
Settlement gain	(2,409)	0
Pension and postretirement medical benefit	(2,136)	264
Postretirement Medical Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost for benefits earned during the period	13	17
Interest cost on projected benefit obligation	149	149
Expected return on plan assets	(320)	(295)
Amortization of net gain (loss)	(308)	(254)
Amortization of prior service benefit	(94)	(162)
Curtailment gain	(1,184)	0
Pension and postretirement medical benefit	$ (1,744)	$ (545)