Other Postretirement Benefits - Changes in the Benefit Obligation and Plan Assets and Other Amounts (Details) - Other Postretirement Benefit Plans - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 26, 2021	Dec. 27, 2020
Change in benefit obligation
Benefit obligation at beginning of year	$ 40,607	$ 43,308
Service cost	46	53	$ 29
Interest cost	731	565	1,026
Plan participants’ contributions	2,271	2,319
Actuarial (gain)/loss	(6,801)	2,254
Benefits paid	(6,158)	(7,892)
Benefit obligation at end of year	30,696	40,607	$ 43,308
Change in plan assets
Fair value of plan assets at beginning of year	0
Employer contributions	3,887	5,573
Plan participants’ contributions	2,271	2,319
Benefits paid	(6,158)	(7,892)
Fair value of plan assets at end of year	0	0
Amount recognized in the Consolidated Balance Sheets
Current liabilities	(4,241)	(4,521)
Noncurrent liabilities	(26,455)	(36,086)
Net amount recognized	(30,696)	(40,607)
Amount recognized in accumulated other comprehensive loss
Actuarial loss	15,537	25,632
Prior service credit	0	(368)
Total	$ 15,537	$ 25,264