Accumulated Other Comprehensive Income (Schedule Of Accumulated Other Comprehensive Income) (Details) - Unrealized Gain On Available-For-Sale Marketable Securities [Member] $ in Thousands	9 Months Ended
	Sep. 28, 2019 USD ($)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income balance, beginning balance	$ 262
Other comprehensive income before reclassifications	1,242
Amounts reclassified from accumulated other comprehensive income	(39)
Net current period change in other comprehensive income	1,203
Accumulated other comprehensive income balance, ending balance	$ 1,465