Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 25, 2021	Dec. 26, 2020
Deferred Tax Assets, Gross [Abstract]
Accounts receivable	$ 951	$ 659
Employment incentives	6,886	6,204
Self-insurance liability	9,324	8,515
Postretirement benefit obligations	7,412	6,527
Net operating loss and credit carryforwards	6,202	7,787
Unrecognized Tax Benefits	2,108	1,751
Other	1,830	1,407
Total deferred tax assets	34,713	32,850
Deferred Tax Liabilities, Gross [Abstract]
Inventories	(16,038)	(13,407)
Unrealized gains on marketable securities	(2,177)	(3,059)
Prepaids	(6,365)	(5,993)
Nondeductible accruals and other		(332)
Depreciation	(125,220)	(113,463)
Total deferred tax liabilities	(149,800)	(136,254)
Net deferred tax liability	$ (115,087)	$ (103,404)