Segment Information - Financial Data by Segment (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	Dec. 31, 2013
Sales to external customers	$ 30,008	$ 22,135	$ 82,555	$ 68,198
Operating income (loss)	1,930	1,409	6,289	5,115
Interest expense, net	153	99	343	242
Other expense (income), net	67	(13)	78	15
Consolidated income before taxes	1,710	1,323	5,868	4,858
Assets	84,943		84,943		68,079
United States
Sales to external customers	25,833	18,273	69,946	55,992
Operating income (loss)	1,819	1,183	5,752	4,454
Assets	74,258		74,258		57,068
Canada
Sales to external customers	2,190	1,782	7,372	6,549
Operating income (loss)	94	130	652	592
Assets	6,090		6,090		5,329
Europe
Sales to external customers	1,985	2,080	5,237	5,657
Operating income (loss)	17	96	(115)	69
Assets	$ 4,595		$ 4,595		$ 5,682