Deferred Warranty Revenue and Warranty Reserve (Details 1) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Schedule of Warranty Activity
Balance, beginning of period	$ 36	$ 61	$ 150
Provision for warranty claims	139	59	105
Product or cash issued to settle claims	(130)	(84)	(194)
Balance, end of period	$ 45	$ 36	$ 61