Employee Benefit Plans (Defined Contribution Plans) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 25, 2021	Sep. 26, 2020	Sep. 25, 2021	Sep. 26, 2020
Non-Collective-Bargaining Plan [Member]
Defined Contribution Plans [Line Items]
Percentage of Employees Covered			85.00%
Employer Matching Contribution, Percentage			1.00%
Employer Matching Contribution, Discretionary Percentage			2.00%
Maximum Annual Contribution Per Employee, Percentage			3.00%
Cost Recognized	$ 501	$ 92	$ 920	$ 265
Collective-Bargaining Plan [Member]
Defined Contribution Plans [Line Items]
Percentage of Employees Covered			15.00%
Maximum Annual Contribution Per Employee, Percentage			2.75%
Cost Recognized	$ 21	$ 19	$ 63	$ 50