Derivatives (Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 26, 2021	Jun. 27, 2020	Jun. 26, 2021	Jun. 27, 2020
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized gain (loss) on interest rate swaps		$ 5	$ (139)	$ 43	$ (1,276)
Effective September 1, 2016 through September 1, 2021 [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Notional Amount		25		25
Effective September 1, 2015 through September 1, 2021 [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Notional Amount		25		25
Interest Rate Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Payments for Other Fees		1,427
Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized gain (loss) on interest rate swaps		5	(139)	43	(1,276)
Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Reclassified from AOCIL on the effective portion into Income	[1],[2]	34	(365)	68	(573)
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net		130		130
Not Designated as Hedging Instrument | Interest Rate Swap [Member] | Other Nonoperating Income (Expense)
Derivative Instruments, Gain (Loss) [Line Items]
Reclassification of unrealized loss into earnings from dedesignated interest rate swaps (2)	[3]	$ 188	$ 0	$ 375	$ 0

[1] The amount of gain (loss) reclassified from AOCIL is included in interest expense on the Company's consolidated condensed financial statements.

[2] The amount of loss expected to be reclassified from AOCIL into earnings during the next 12 months subsequent to June 26, 2021 is $130.

[3] The amount of gain (loss) recognized in income on the dedesignated portion of interest rate swaps is included in other income or other expense on the Company's Consolidated Condensed Statements of Operations. The amount of expense recognized on the Company's Consolidated Statements of Operations for the terminated portion of interest rate swaps is included in interest expense.