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Revenue Sources and Concentration of Sales (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Revenues	$ 108,447	$ 229,958
Sales Revenue, Net [Member] | Customers Outside of US [Member]
Revenues	$ 1,350	$ 6,693
Sales Revenue, Net [Member] | Customer Concentration Risk [Member] | Largest Customer [Member]
Concentration Risk, Percentage	44.00%	15.00%
Sales Revenue, Net [Member] | Customer Concentration Risk [Member] | Second Largest Customer [Member]
Concentration Risk, Percentage	21.00%	12.00%
Sales Revenue, Net [Member] | Customer Concentration Risk [Member] | Third Largest Customer [Member]
Concentration Risk, Percentage	12.00%	12.00%

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- Definition

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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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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