STOCK-BASED COMPENSATION - Stock option activity (Details) - Stock options - $ / shares	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019
Number of Shares Underlying Options
Outstanding, beginning of period	213,078	232,322
Exercised	(2,524)	(14,844)
Forfeited/expired		(2,000)
Outstanding, end of period	210,554	215,478
Weighted Average Exercise Price
Outstanding, beginning of period	$ 16.92	$ 16.66
Exercised	12.90	12.62
Forfeited/expired		18.25
Outstanding, end of period	$ 16.97	$ 16.93

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

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- Definition

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

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- Definition

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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No definition available.

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

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