Goodwill & Other Identifiable Intangible Assets (Details 2) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Goodwill & Intangible Assets
Weighted Average Amortization Period	13 years		13 years 1 month 6 days
Gross Carrying Amount	$ 22,876,000		$ 22,642,000
Foreign Exchange	(223,000)		(107,000)
Accumulated Amortization	(15,663,000)		(15,147,000)
Net Carrying Amount	6,990,000		7,388,000
Amortization expense	500,000	400,000
Remaining period of 2013	1,500,000
Estimated amortization expense to be recognized during the next five years
2014	1,948,000
2015	1,318,000
2016	1,072,000
2017	301,000
2018	141,000
Patents
Goodwill & Intangible Assets
Weighted Average Amortization Period	20 years		20 years
Gross Carrying Amount	676,000		676,000
Accumulated Amortization	(559,000)		(548,000)
Net Carrying Amount	117,000		128,000
Customer Relationships
Goodwill & Intangible Assets
Weighted Average Amortization Period	15 years 10 months 24 days		15 years 10 months 24 days
Gross Carrying Amount	10,450,000		10,450,000
Foreign Exchange	(253,000)		(223,000)
Accumulated Amortization	(8,430,000)		(8,311,000)
Net Carrying Amount	1,767,000		1,916,000
Product Certification
Goodwill & Intangible Assets
Weighted Average Amortization Period	5 years 4 months 24 days		5 years 4 months 24 days
Gross Carrying Amount	7,603,000		7,369,000
Foreign Exchange	(11,000)		(3,000)
Accumulated Amortization	(4,224,000)		(3,917,000)
Net Carrying Amount	3,368,000		3,449,000
Unpatented Technology
Goodwill & Intangible Assets
Weighted Average Amortization Period	18 years 4 months 24 days		18 years 4 months 24 days
Gross Carrying Amount	3,183,000		3,183,000
Accumulated Amortization	(2,258,000)		(2,191,000)
Net Carrying Amount	925,000		992,000
Licenses
Goodwill & Intangible Assets
Weighted Average Amortization Period	20 years		20 years
Gross Carrying Amount	964,000		964,000
Foreign Exchange	41,000		119,000
Accumulated Amortization	(192,000)		(180,000)
Net Carrying Amount	$ 813,000		$ 903,000