Other Financial Statement Data (Schedule Of Changes In Deferred Warranty Revenue) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Movement in Extended Product Warranty Accrual [Roll Forward]
Balance at beginning of period	$ 199	$ 475
Revenue deferrals	490	277
Amortization of deferred revenue	(330)	(518)
Total deferred warranty revenue	359	234
Current portion of deferred warranty revenue	(278)	(227)
Long-term deferred warranty revenue	$ 81	$ 7