Other Accrued Liabilities (Details 1) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Accrued warranty
Balance at beginning of period	$ 140,000	$ 408,000	$ 227,000	$ 510,000
Accruals for warranties issued during the period	14,000	107,000	94,000	392,000
Warranty claims	(49,000)	(223,000)	(216,000)	(610,000)
Balance at end of period	$ 105,000	$ 292,000	$ 105,000	$ 292,000