Other Financial Statement Data (Schedule Of Changes In Deferred Warranty Revenue) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Other Financial Statement Data [Abstract]
Balance at beginning of period	$ 806	$ 787
Revenue deferrals	230	489
Amortization of deferred revenue	(454)	(470)
Total deferred warranty revenue	582	806
Current portion of deferred warranty revenue	(436)	(453)
Long-term deferred warranty revenue	$ 146	$ 353