Guarantees (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Product Warranty [Abstract]
Period of warranty	12 months
Change in warranty accrual [Roll Forward]
Beginning accrued warranty and related costs	$ 588,000	$ 1,003,000
Accruals for warranties issued during the year	789,000	362,000
Adjustments related to pre-existing warranties including expirations and changes in estimates	412,000	(450,000)
Cost of warranty repair	(741,000)	(327,000)
Ending accrued warranty and related costs	$ 1,048,000	$ 588,000