Segment Reporting and Geographic Information (Details) - Company`s reportable segments (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Revenues
Net sales	$ 12,591	$ 12,555	$ 25,053	$ 25,862
(Loss) income from operations
Income (loss) from operations	(560)	(1,169)	(2,013)	(3,163)
Operating Segments [Member] | Heavy Duty Diesel Systems [Member]
Revenues
Net sales	7,018	7,109	14,176	14,393
(Loss) income from operations
Income (loss) from operations	660	(81)	938	(418)
Operating Segments [Member] | Catalyst [Member]
Revenues
Net sales	6,289	6,296	12,100	12,752
(Loss) income from operations
Income (loss) from operations	361	132	583	253
Operating Segments [Member] | Corporate Segment [Member]
Revenues
Net sales
(Loss) income from operations
Income (loss) from operations	(1,591)	(1,259)	(3,524)	(3,076)
Intersegment Eliminations [Member]
Revenues
Net sales	(716)	(850)	(1,223)	(1,283)
(Loss) income from operations
Income (loss) from operations	$ 10	$ 39	$ (10)	$ 78