Segment Reporting and Geographic Information (Details) - Company`s reportable segments (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Segment Reporting Information [Line Items]
Net sales	$ 12,462	$ 13,307
Income (loss) from operations	(1,453)	(1,994)
Operating Segments [Member] | Heavy Duty Diesel Systems [Member]
Segment Reporting Information [Line Items]
Net sales	7,158	7,284
Income (loss) from operations	278	(337)
Operating Segments [Member] | Catalyst [Member]
Segment Reporting Information [Line Items]
Net sales	5,811	6,456
Income (loss) from operations	222	121
Operating Segments [Member] | Corporate Segment [Member]
Segment Reporting Information [Line Items]
Net sales
Income (loss) from operations	(1,933)	(1,817)
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Net sales	(507)	(433)
Income (loss) from operations	$ (20)	$ 39