Accumulated Other Comprehensive Income (Schedule of Accumulated Other Comprehensive Income) (Details) - Accumulated Net Investment Gain (Loss) Attributable to Parent [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income balance, beginning balance	$ 4,761	$ 4,829
Other comprehensive income (loss) before reclassifications	348	(52)
Amounts reclassified from accumulated other comprehensive income	(257)	(16)
Other comprehensive income (loss), net of tax	91	(68)
Accumulated other comprehensive income balance, ending balance	$ 4,852	$ 4,761