STOCKHOLDERS' EQUITY - Stock options (Details) - USD ($)	3 Months Ended	9 Months Ended	12 Months Ended
Sep. 30, 2019	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
STOCKHOLDERS' EQUITY
Number of Options, Grants	653,210	653,210	732,869
Number of Options, Exercised		15,000	58,190
Employee Stock Option [Member]
STOCKHOLDERS' EQUITY
Number of Options, Outstanding at Beginning of Year		3,569,000
Number of Options, Grants		653,000
Number of Options, Exercised		15,000
Number of Option, Forfeited/cancelled/expired/settled		10,000
Number of Options, Balance at End of Year	4,197,000	4,197,000		3,569,000
Number of Options, Vested and expected to vest	4,143,000	4,143,000
Number of Options, Unvested	835,000	835,000
Number of Options, Exercisable	3,362,000	3,362,000
Weighted-Average Exercise Price, Outstanding at Beginning of Year (in dollars per share)		$ 2.12
Weighted-Average Exercise Price, Grants (in dollars per share)		2.17
Weighted-Average Exercise Price, Exercised (in dollars per share)		1.90
Weighted-Average Exercise Price, Forfeited/cancelled/expired/settled (in dollars per share)		1.90
Weighted-Average Exercise Price, Balance at End of Year (in dollars per share)	$ 2.13	2.13		$ 2.12
Weighted-Average Exercise Price, Vested and expected to vest (in dollars per share)	2.13	2.13
Weighted-Average Exercise Price, Unvested (in dollars per share)	2.11	2.11
Weighted-Average Exercise Price, Exercisable (in dollars per share)	$ 2.13	$ 2.13
Weighted-Average Remaining Contractual Term, Outstanding (in years)		6 years 11 months 12 days		7 years 2 months 9 days
Weighted-Average Remaining Contractual Term, Vested and expected to vest (in years)		6 years 11 months 5 days
Weighted-Average Remaining Contractual Term, Unvested (in years)		9 years 4 months 10 days
Weighted-Average Remaining Contractual Term, Exercisable (in years)				6 years 4 months 6 days
Aggregate Intrinsic Value, Outstanding	$ 296,000	$ 296,000		$ 130,000
Aggregate Intrinsic Value, Vested and expected to vest	295,000	295,000
Aggregate Intrinsic Value, Unvested	4,000	4,000
Aggregate Intrinsic Value, Exercisable	$ 292,000	$ 292,000

The aggregate intrinsic value of non vested options.

No definition available.

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The weighted average remaining contractual term for options not vested.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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For presentations that combine terminations, the number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan or that expired.

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Weighted average price of options that were either forfeited or expired.

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

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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Number of options outstanding, including both vested and non-vested options.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Amount by which current fair value of underlying stock exceeds exercise price of fully vested and expected to vest exercisable or convertible options. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Amount by which current fair value of underlying stock exceeds exercise price of fully vested and expected to vest options outstanding. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Number of fully vested and expected to vest options outstanding that can be converted into shares under option plan. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Weighted-average exercise price, at which grantee can acquire shares reserved for issuance, for fully vested and expected to vest options outstanding. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Number of non-vested options outstanding.

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

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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Weighted average remaining contractual term for fully vested and expected to vest options outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Number of share options (or share units) exercised during the current period.

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