Segment Information - Financial Data by Segment (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Sales to external customers	$ 33,954	$ 33,396	$ 56,791	$ 52,548
Operating income (loss)	3,875	3,738	4,701	4,363
Interest expense, net	141	106	271	188
Other (income) expense, net	(20)	(3)	56	16
Consolidated income before income taxes	3,754	3,635	4,374	4,159
Assets	89,421		89,421		$ 79,308
United States
Sales to external customers	29,649	27,870	49,782	43,974
Operating income (loss)	3,552	3,239	4,522	3,916
Assets	79,605		79,605		70,526
Canada
Sales to external customers	2,813	3,673	4,054	5,184
Operating income (loss)	282	527	175	559
Assets	5,550		5,550		4,363
Europe
Sales to external customers	1,492	1,853	2,955	3,390
Operating income (loss)	41	$ (28)	4	$ (112)
Assets	$ 4,266		$ 4,266		$ 4,419

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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