Stock-Based Compensation (Details 1) - $ / shares	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Stock Options
Risk-free interest rate	0.40%	1.70%
Expected term	6 years 1 month 6 days	3 years 1 month 6 days
Volatility	42.50%	35.60%
Expected dividend	0.00%	0.00%
Weighted average grant-date fair value	$ .55	$ .52
ESPP
Risk-free interest rate	0.20%	2.00%
Expected term	6 months	6 months
Volatility	74.40%	42.40%
Expected dividend	0.00%	0.00%
Weighted average grant-date fair value	$ .34	$ .43

The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

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- Definition

The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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- Definition

The risk-free interest rate assumption that is used in valuing an option on its own shares.

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- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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- Definition

Expected term of award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(i)
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.D.2)
-URI http://asc.fasb.org/extlink&oid=115993241&loc=d3e301413-122809

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