Postretirement and Postemployment Benefits - Amounts Recognized in Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
Sep. 25, 2022	Sep. 26, 2021
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Unrecognized net actuarial gain (loss)	$ 10,893	$ 36,965
Other Postretirement Benefits Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Unrecognized net actuarial gain (loss)	14,298	14,071
Unrecognized prior service benefit	3,029	3,676
Amounts recognized in accumulated other comprehensive income (loss)	$ 17,327	$ 17,747

Amount, before tax, after reclassification adjustment, of (increase) decrease in accumulated other comprehensive income for defined benefit plan.

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