Warranties (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Change in the Company's warranty reserve
Liability, beginning of period	$ 1,220	$ 1,051	$ 1,374	$ 930
Provision for warranties issued during the year, net of adjustments	567	322	877	659
Adjustments to warranties issued during previous years	(43)	137	(396)	34
Warranty claims	(225)	(224)	(336)	(337)
Liability, end of period	$ 1,519	$ 1,286	$ 1,519	$ 1,286