Other Financial Statement Data (Schedule Of Changes In Deferred Warranty Revenue) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Movement in Extended Product Warranty Accrual [Roll Forward]
Balance at beginning of period	$ 199	$ 475
Revenue deferrals	203	212
Amortization of deferred revenue	(226)	(365)
Total deferred warranty revenue	176	322
Current portion of deferred warranty revenue	(171)	(307)
Long-term deferred warranty revenue	$ 5	$ 15