Discontinued Operations (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 25, 2021 USD ($) installment	Dec. 26, 2020 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Accrual for environmental remediation obligation	$ 1,913	$ 1,924
Discontinued Operations, Disposed of by Sale | Commercial Divestiture
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net Proceeds, including escrowed funds	20,500
Contract Liabilities	$ 3,127
Noncompete term	5 years
Escrow deposit	$ 2,100
Number of installments | installment	2
Initial amount paid, percentage	50.00%
Initial amount paid, period	90 days
Remaining amount paid, period	18 months
Escrow deposit, current	$ 1,025
Payments for Deposits with Other Institutions	2,100
Effect of LIFO inventory liquidation on income	$ 3,174