1. Summary of Significant Accounting Policies (Details Narrative) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Significant Accounting Policies [Line Items]
Disbursements	$ 388	$ 411	$ 624
Depreciation expense	9,003	8,526	8,689
Goodwill, carrying amount	9,730	9,730	9,730
Allowances for doubtful accounts	$ 21	$ 28	$ 71
One Customer \| Accounts Receivable
Significant Accounting Policies [Line Items]
Risk concentration	10.00%	15.50%
Patent And License [Member] \| Minimum [Member]
Significant Accounting Policies [Line Items]
Patents and licenses, useful lives	7 years
Patent And License [Member] \| Maximum [Member]
Significant Accounting Policies [Line Items]
Patents and licenses, useful lives	20 years

Significant Accounting Policies [Line Items]

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Carrying value as of the balance sheet date of obligations incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

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Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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