Accumulated Other Comprehensive Income (Schedule Of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated change in effective tax rates	$ 0
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income balance, beginning balance	4,852	$ 4,761
Other comprehensive income (loss) before reclassifications	(43)	348
Accumulated change in effective tax rates	1,042
Amounts reclassified from accumulated other comprehensive income	29	(257)
Net current period other comprehensive income	1,028	91
Accumulated other comprehensive income balance, ending balance	$ 5,880	$ 4,852