Pension, Postretirement and Postemployment Benefits - Assumptions used to determine year-end Pension and Postretirement Benefit Obligation (Details)	12 Months Ended
	Dec. 31, 2023	Dec. 25, 2022
Pension
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted average discount rate	5.23%	5.61%
Postretirement
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted average discount rate	5.20%	5.58%
Health care cost trend rate assumed for next year	6.75%	7.00%
Rate to which the cost trend rate is assumed to decline (ultimate trend rate)	5.00%	5.00%