Employee Benefit Plans (Other Postretirement Plans - Funded Status) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 26, 2020	Dec. 28, 2019	Dec. 29, 2018
Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, before Tax [Abstract]
Unrecognized actuarial gains	$ (309)
Totals	(309)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position [Abstract]
Accrued expenses	17	$ 16
Other long-term liabilities	373	344
Total liability	390	360
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	0	0
Employer contributions	1	1
Benefits Paid	1	1
Fair value of plan assets at end of year	0	0	$ 0
Unfunded amount	(390)	(360)
Defined Benefit Plan, Expected Amortization, Next Fiscal Year [Abstract]
Unrecognized actuarial gains	(24)
Totals	(24)
Defined Benefit Plan, Expected Future Benefit Payment [Abstract]
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months	17
Defined Benefit Plan, Expected Future Benefit Payment, Year Two	16
Defined Benefit Plan, Expected Future Benefit Payment, Year Three	16
Defined Benefit Plan, Expected Future Benefit Payment, Year Four	16
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	16
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter	79
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	8	7	8
Interest cost	17	17	17
Amortization of prior service credits	0	(3)	(4)
Recognized net actuarial gains	(25)	(27)	(28)
Net periodic benefit cost (credit)	$ 0	$ (6)	(7)
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Discount rate (benefit obligation)	3.25%	3.50%
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]
Defined Benefit Plan, Benefit Obligation	$ 390	$ 360	331
Service cost	8	7	8
Interest cost	17	17	$ 17
Actuarial (gain) loss	6	6
Benefits Paid	$ 1	$ 1