Inventories And Warranties (Schedule Of Changes In Deferred Warranty Revenue) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Inventories And Warranties [Abstract]
Balance at beginning of period	$ 582	$ 806
Revenue deferrals	94	46
Amortization of deferred revenue	(135)	(105)
Total deferred warranty revenue	541	747
Current portion of deferred warranty revenue	(361)	(482)
Long-term deferred warranty revenue	$ 180	$ 265	$ 146