General (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 29, 2016	Sep. 24, 2015	Sep. 29, 2016	Sep. 24, 2015
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Begining Balance, Swap Agreements				$ 9	$ 116
Other comprehensive loss before reclassifications, Swap Agreements		$ 0	$ (113)	(143)	(282)
Amounts reclassified from accumulated other comprehensive loss, Swap Agreements	[1]			134	87
Net other comprehensive loss, Swap Agreements				(9)	(195)
Ending Balance, Swap Agreements		0	(79)	0	(79)
Beginning Balance, Available for Sale Investments				(11)	(11)
Other comprehensive loss before reclassifications, Available for Sale Investments				0	0
Amounts reclassified from accumulated other comprehensive loss, Available for Sale Investments	[1]			0	0
Net other comprehensive loss, Available for Sale Investments				0	0
Ending Balance, Available for Sale Investments		(11)	(11)	(11)	(11)
Beginning Balance, Pension Obligation				(5,219)	(4,580)
Amortization of the net actuarial loss and prior service credit, pension obligation		163	0	163	199
Other comprehensive loss before reclassifications, Pension Obligation		0	0	0	(902)
Amounts reclassified from accumulated other comprehensive loss, Pension Obligation	[1]			0	0
Net other comprehensive income loss, Pension Obligation				163	(703)
Ending Balance, Pension Obligation		(5,056)	(5,283)	(5,056)	(5,283)
Beginning Balance, Accumulated Other Comprehensive Loss				(5,221)	(4,475)
Amortization of the net actuarial loss and prior service credit, accumulated other comprehensive loss				163	199
Other comprehensive loss before reclassifications, Accumulated Other Comprehensive Loss				(143)	(1,184)
Amounts reclassified from accumulated other comprehensive loss, Accumulated Other Comprehensive Loss	[1]			134	87
Other comprehensive income (loss)		163	(85)	154	(898)
Ending Balance, Accumulated Other Comprehensive Loss		$ (5,067)	$ (5,373)	$ (5,067)	$ (5,373)

[1] Amounts are included in interest expense in the consolidated statements of earnings.