Major Customers (Schedule Of Sales To Largest Customers) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
International Business Machines Corporation [Member]
Entity Wide Revenue Major Customer [Line Items]
Sales to our largest customers	$ 0	$ 284,098	$ 312,611
Arris Group, Inc. [Member]
Entity Wide Revenue Major Customer [Line Items]
Sales to our largest customers	$ 0	$ 0	$ 315,688