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Number of remaining number of shares of common stock available for issuance under the plan

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The value of the financial instrument(s) that the original debt is being converted into in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

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The number of shares issued in exchange for the original debt being converted in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or payments in the period.

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Face (par) amount of debt instrument at time of issuance.

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Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

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Weighted-average period over which cost not yet recognized is expected to be recognized for 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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Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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

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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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Number of shares authorized for issuance under share-based payment arrangement.

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

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

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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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Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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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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Ratio applied to the conversion of stock split, for example but not limited to, one share converted to two or two shares converted to one.

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SHARE CAPITAL - Additional information (Details)				1 Months Ended				12 Months Ended
SHARE CAPITAL - Additional information (Details)	Dec. 09, 2019	Sep. 13, 2018 USD ($) $ / shares shares	Dec. 07, 2016 shares	Sep. 30, 2019 USD ($) $ / shares shares	Jun. 30, 2019 USD ($) $ / shares shares	May 22, 2018 USD ($) shares	Jul. 24, 2017 USD ($)	Dec. 31, 2019 USD ($) $ / shares shares	Dec. 31, 2018 USD ($) shares	Dec. 31, 2017 USD ($)	Dec. 02, 2016 USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reverse stock split ratio	0.1
Shares of Common Stock remain available for grant under the plan								690,182
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized \| $								$ 800,000
Debt Conversion, Converted Instrument, Amount \| $								$ 0	$ 2,285,000	$ 16,263,000
Debt Conversion, Converted Instrument, Shares Issued			2,384,673						1,123,964
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition								1 year 26 days
4.5% Convertible Notes [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Debt Conversion, Converted Instrument, Amount \| $						$ 2,230,000
Debt Conversion, Converted Instrument, Shares Issued						261,363
Principal amount \| $						$ 3,423,000	$ 9,000,000
Debt Instrument Maturity Year							2018
2021 Notes [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Principal amount \| $							$ 10,000,000				$ 22,500,000
Debt Instrument Maturity Year							2021
Four Point Five Percentage Convertible Notes 2022 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Principal amount \| $							$ 8,550,000
Debt Instrument Maturity Year							2022
2006 Employee Stock Incentive Plan Member
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized								2,384,165
Officers And Certain Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures		236,000
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price \| $ / shares		$ 5.1
Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share Based Compensation Arrangement By Share Based Payment Award Grant Date Fair Value \| $								$ 449,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures		400,000
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price \| $ / shares								$ 4.69
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross								160,000
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period								4 years
Non-executive Officers [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price \| $ / shares		$ 5.1
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period		10 years		10 years	10 years
Share Based Compensation Arrangement By Share Based Payment Award Grant Date Fair Value \| $		$ 1,900,000		$ 97,000	$ 449,000
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate		64.30%		66.48%	65.30%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate		2.90%		1.695%	1.80%
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures		636,000
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period				4 years	4 years
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term		6 years		6 years	6 years
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate		0.00%		0.00%	0.00%
Employee Stock Option [Member] \| Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price \| $ / shares		$ 5.6
Employee Stock Option [Member] \| Chief Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price \| $ / shares					$ 4.69
Employee Stock Option [Member] \| Chief Executive Officer [Member] \| 2006 Employee Stock Incentive Plan Member
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price \| $ / shares					$ 4.69
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross					160,000
Employee Stock Option [Member] \| Chief Financial Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price \| $ / shares				$ 2.00
Employee Stock Option [Member] \| Chief Financial Officer [Member] \| 2006 Employee Stock Incentive Plan Member
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price \| $ / shares				$ 2.00
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross				80,000
Restricted Stock Units [Member] \| Chief Financial Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate value of Restricted Stock Units that will be granted, contingent upon certain conditions \| $				$ 100,000