Accumulated Other Comprehensive Income (Schedule Of Accumulated Other Comprehensive Income) (Details) - Unrealized Gain On Available-For-Sale Marketable Securities [Member] $ in Thousands	3 Months Ended
	Mar. 30, 2019 USD ($)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income balance, beginning balance	$ 262
Other comprehensive income before reclassifications	621
Amounts reclassified from accumulated other comprehensive income	0
Net current period change in other comprehensive income	621
Accumulated other comprehensive income balance, ending balance	$ 883