Other Accrued Liabilities (Details 1) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Accrued warranty
Balance at beginning of period	$ 93,000	$ 186,000	$ 117,000	$ 227,000
Accruals for warranties issued during the period	46,000	55,000	57,000	80,000
Warranty claims	(28,000)	(101,000)	(63,000)	(167,000)
Balance at end of period	$ 111,000	$ 140,000	$ 111,000	$ 140,000