STOCK-BASED COMPENSATION - Stock Options Activity (Details)	9 Months Ended
Sep. 30, 2019 USD ($) $ / shares shares
Number of Options
Outstanding, Beginning Balance, Number of Options \| shares	75,062
Granted, Number of Options \| shares
Exercised, Number of Options \| shares	(32,810)
Expired/Forfeited, Number of Options \| shares	(502)
Outstanding, Ending Balance, Number of Options \| shares	41,750
Weighted Average Exercise Price
Outstanding, Beginning Balance, Weighted Average Exercise Price \| $ / shares	$ 7.95
Granted, Weighted Average Exercise Price \| $ / shares
Exercised, Weighted Average Exercise Price \| $ / shares	6.30
Expired/Forfeited, Weighted Average Exercise Price \| $ / shares	6.00
Outstanding, Ending Balance, Weighted Average Exercise Price \| $ / shares	$ 9.27
Additional information
Options Outstanding, Weighted Average Remaining Contractual Term	7 months 6 days
Options outstanding at end of year, Aggregate grant date fair value \| $	$ 387,180
Options exercisable at end of year (in shares) \| shares	41,750
Options exercisable at end of year, Weighted Average Exercise Price \| $ / shares	$ 9.27
Weighted average remaining contractual term	7 months 6 days
Intrinsic value of options exercisable \| $	$ 387,180

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

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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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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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

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

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