Warranties (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Change in the Company's warranty reserve
Liability, beginning of period	$ 1,654	$ 1,519	$ 1,385	$ 1,374
Provision for warranties issued during the year, net of adjustments	335	226	931	1,103
Adjustments to warranties issued during previous years	(97)	(314)	(120)	(710)
Warranty claims	(248)	(144)	(552)	(480)
Liability, end of period	$ 1,644	$ 1,287	$ 1,644	$ 1,287