SHARE-BASED COMPENSATION - Stock Option Valuation (Details) - shares	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Stock Option Valuation
Granted (in shares)	648,000
Nonemployees
Stock Option Valuation
Granted (in shares)	0
Stock options \| Employees
Stock Option Valuation
Risk-free interest rate	1.78%	2.89%
Expected term (in years)	6 years 3 months 18 days	6 years 3 months 18 days
Expected volatility	60.60%	57.80%
Stock options \| Nonemployees
Stock Option Valuation
Risk-free interest rate		3.00%
Expected term (in years)		10 years
Expected volatility		62.70%

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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

Gross number of share options (or share units) granted during the period.

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No definition available.

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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
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