Segment Information - Financial Data by Segment (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Sales to external customers	$ 33,396	$ 28,412	$ 52,548	$ 46,063
Operating income (loss)	3,738	3,192	4,363	3,706
Interest expense, net	106	74	188	142
Other (income) expense, net	(3)	25	16	28
Consolidated income before taxes	3,635	3,093	4,159	3,536
Assets	87,987		87,987		68,079
United States
Sales to external customers	27,870	23,496	43,974	37,721
Operating income (loss)	3,239	2,701	3,916	3,267
Assets	75,565		75,565		57,068
Canada
Sales to external customers	3,673	3,139	5,184	4,765
Operating income (loss)	527	475	559	463
Assets	7,676		7,676		5,329
Europe
Sales to external customers	1,853	1,777	3,390	3,577
Operating income (loss)	(28)	16	(112)	(24)
Assets	$ 4,746		$ 4,746		$ 5,682