Warranties (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Change in the Company's warranty reserve
Liability, beginning of year	$ 1,374	$ 930	$ 1,151
Provision for warranties issued during the year, net of adjustments	1,453	1,318	1,098
Provision for warranties issued in previous years, net of adjustments	(788)	199	(466)
Warranty claims	(654)	(1,073)	(853)
Liability, end of year	$ 1,385	$ 1,374	$ 930