Inventories And Warranties (Schedule Of Changes In Deferred Warranty Revenue) (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Inventories And Warranties [Abstract]
Balance at beginning of period	$ 806	$ 787
Revenue deferrals	181	342
Amortization of deferred revenue	(336)	(350)
Total deferred warranty revenue	651	779
Current portion of deferred warranty revenue	(462)	(574)
Long-term deferred warranty revenue	$ 189	$ 205	$ 353