Pension, Postretirement and Postemployment Defined Benefit Plans - Net Periodic Cost (Benefit) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 25, 2023	Jun. 26, 2022	Jun. 25, 2023	Jun. 26, 2022
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost for benefits earned during the period	$ 5	$ 287	$ 15	$ 1,030
Interest cost on projected benefit obligation	2,592	2,001	7,776	5,939
Expected return on plan assets	(2,548)	(4,535)	(7,644)	(13,606)
Amortization of net gain (loss)	2	(687)	6	(2,633)
Amortization of prior service benefit	213	212	639	424
Curtailment gain		0	0	(1,027)
Pension and postretirement medical cost (benefit)	264	(2,722)	792	(9,873)
Postretirement Medical Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost for benefits earned during the period	17	27	51	81
Interest cost on projected benefit obligation	149	85	447	255
Expected return on plan assets	(295)	(263)	(885)	(789)
Amortization of net gain (loss)	(254)	(249)	(762)	(747)
Amortization of prior service benefit	(162)	(162)	(486)	(486)
Pension and postretirement medical cost (benefit)	$ (545)	$ (562)	$ (1,635)	$ (1,686)