STOCK-BASED COMPENSATION - Outstanding options (Details) - USD ($)	3 Months Ended	12 Months Ended
Mar. 31, 2022	Dec. 31, 2021
STOCK-BASED COMPENSATION
Number of Shares, Outstanding	178,499
Number of Shares, Granted	0
Number of Shares, Exercised	0
Number of Shares, Forfeited	0
Number of Shares, Expired	0
Number of Shares, Outstanding	178,499	178,499
Number of Shares, Vested	175,831
Weighted Average Exercise Price per share, Outstanding (in dollars per share)	$ 6.76
Weighted Average Exercise Price per share, Granted (in dollars per share)	0
Weighted Average Exercise Price per share, Exercised (in dollars per share)	0
Weighted Average Exercise Price per share, Forfeited (in dollars per share)	0
Weighted Average Exercise Price per share, Expired (in dollars per share)	0
Weighted Average Exercise Price per share, Outstanding (in dollars per share)	6.76	$ 6.76
Weighted Average Exercise Price per share, Vested (in dollars per share)	$ 6.73
Weighted Average Remaining Contractual Life, Outstanding (Years)	3 years 2 months 12 days	3 years 4 months 24 days
Weighted Average Remaining Contractual Life, Vested (Years)	3 years 1 month 6 days
Aggregate Intrinsic Value, Outstanding (in dollars)	$ 56,692	$ 60,643
Aggregate Intrinsic Value, Vested (in dollars)	$ 56,692

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Number of options or other stock instruments for which the right to exercise has lapsed under the terms of the plan agreements.

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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.

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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 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 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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