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SHAREHOLDERS' EQUITY - Non-vested Options Outstanding and Exercisable (Details) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares
Stock options granted (in shares)	5,097,000	3,050,000	375,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value
Stock options granted (in dollars per share)	$ 1.22	$ 1.73	$ 1.90
Amended and Restated Equity Incentive Plan and Non-related Plan Options
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares
Balance at the beginning of the period (in shares)	3,034
Stock options granted (in shares)	5,097
Stock options cancelled/forfeited (in shares)	(1,172)
Stock options vested (in shares)	(866)
Balance at the end of the period (in shares)	6,093	3,034
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value
Balance at the beginning of the period (in dollars per share)	$ 0.64
Stock options granted (in dollars per share)	0.40
Stock options cancelled/forfeited (in dollars per share)	0.60
Stock options vested (in dollars per share)	0.71
Balance at the end of the period (in dollars per share)	$ 0.44	$ 0.64

X

- Definition

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

+ References

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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.

+ References

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 (d)(1)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

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- Definition

Number of non-vested options outstanding.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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- Definition

Number of non-vested options forfeited.

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- Definition

Weighted average grant-date fair value of non-vested options forfeited.

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Weighted average grant-date fair value of non-vested options outstanding.

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Number of options vested.

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Weighted average grant-date fair value of options vested.

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