3. Patents and Licenses (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Acquired Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization	$ 12,181	$ 12,062
Patent And License [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted Average Original Life (years)	15 years 8 months 1 day	15 years 8 months 1 day
Gross Carrying Amount	$ 13,840	$ 13,840
Accumulated Amortization	$ 12,181	$ 12,062

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No definition available.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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