Employee Benefit Plans (Defined Contribution Plans) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 26, 2021	Jun. 27, 2020	Jun. 26, 2021	Jun. 27, 2020
Non-Collective-Bargaining Plan [Member]
Defined Contribution Plans [Line Items]
Percentage of Employees Covered			84.00%
Employer Matching Contribution, Percentage			1.00%
Employer Matching Contribution, Discretionary Percentage			2.00%
Maximum Annual Contribution Per Employee, Percentage			3.00%
Cost Recognized	$ 195	$ 67	$ 419	$ 173
Collective-Bargaining Plan [Member]
Defined Contribution Plans [Line Items]
Percentage of Employees Covered			16.00%
Maximum Annual Contribution Per Employee, Percentage			2.75%
Cost Recognized	$ 33	$ 17	$ 54	$ 43