Goodwill and Other Identifiable Intangible Assets - Summary of Identifiable Intangible Assets (Details 2) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Identifiable intangible Assets
Gross Carrying Amount	$ 26,227	$ 24,743
Foreign Exchange	(517)	(449)
Accumulated Amortization	(19,749)	(18,013)
Net Carrying Amount	5,961	6,281
Amortization expense	1,700	$ 2,200	$ 2,100
Estimated amortization expense to be recognized during the next five years
2016	1,549
2017	901
2018	717
2019	510
2020	$ 420
Weighted Average
Identifiable intangible Assets
Amortization Period	13 years 9 months 18 days	12 years 8 months 12 days
Patents
Identifiable intangible Assets
Gross Carrying Amount	$ 676	$ 676
Accumulated Amortization	(656)	(636)
Net Carrying Amount	$ 20	$ 40
Patents | Weighted Average
Identifiable intangible Assets
Amortization Period	20 years	20 years
Customer Relationships
Identifiable intangible Assets
Gross Carrying Amount	$ 10,450	$ 10,450
Foreign Exchange	(303)	(270)
Accumulated Amortization	(9,526)	(9,198)
Net Carrying Amount	$ 621	$ 982
Customer Relationships | Weighted Average
Identifiable intangible Assets
Amortization Period	15 years 10 months 24 days	15 years 10 months 24 days
Product Certification
Identifiable intangible Assets
Gross Carrying Amount	$ 10,954	$ 9,470
Foreign Exchange	(95)	(62)
Accumulated Amortization	(6,259)	(5,182)
Net Carrying Amount	$ 4,600	$ 4,226
Product Certification | Weighted Average
Identifiable intangible Assets
Amortization Period	7 years 2 months 12 days	6 years
Unpatented Technology
Identifiable intangible Assets
Gross Carrying Amount	$ 3,183	$ 3,183
Accumulated Amortization	(2,996)	(2,722)
Net Carrying Amount	$ 187	$ 461
Unpatented Technology | Weighted Average
Identifiable intangible Assets
Amortization Period	20 years	18 years 4 months 24 days
Licenses
Identifiable intangible Assets
Gross Carrying Amount	$ 964	$ 964
Foreign Exchange	(119)	(117)
Accumulated Amortization	(312)	(275)
Net Carrying Amount	$ 533	$ 572
Licenses | Weighted Average
Identifiable intangible Assets
Amortization Period	20 years	20 years