Pension Benefits - Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income (Details) - Pension Plan - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 26, 2021	Dec. 27, 2020
Pension Benefits
Net actuarial gain	$ (22,500)	$ (25,585)	$ (4,172)
Prior service cost	0	0	0
Amortization of loss	(19,637)	(27,500)	(27,959)
Amortization of prior service credit	1,897	1,890	1,894
Effect of settlement	0	0	(80,641)
Total recognized in other comprehensive income	(40,240)	(51,195)	(110,878)
Net periodic pension cost	14,634	18,805	99,857
Total recognized in net periodic pension benefit cost and other comprehensive income	(25,606)	(32,390)	(11,021)
Defined contribution plan, cost recognized	$ 29,000	$ 33,000	$ 27,000