EARNINGS PER SHARE - Computation of earnings per share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Earnings Per Share [Abstract]
Net income	$ 8,824	$ 6,256	$ 6,685
Less: Undistributed earnings allocated to participating securities	(111)	(55)	(52)
Net income allocated to common stock	8,713	6,201	6,633
Weighted average common shares issued	2,798	2,779	2,755
Less: Unvested restricted stock awards	(35)	(24)	(22)
Weighted average common shares outstanding used to calculate basic earnings per common share	2,763	2,755	2,733
Add: Dilutive effect of stock options	17	19	16
Weighted average common shares outstanding used to calculate diluted earnings per common share	$ 2,780	$ 2,774	$ 2,749
Earnings per common share (basic)	$ 3.15	$ 2.25	$ 2.43
Earnings per common share (diluted)	$ 3.13	$ 2.24	$ 2.41

Amount of increase (decrease) to net income used for calculating diluted earnings per share (EPS), resulting from the assumed exercise of stock options or restrictive stock units (RSUs).

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Amount of increase (decrease) to net income used for calculating diluted earnings per share (EPS), resulting from the assumed exercise stock options, restrictive stock units (RSUs), convertible preferred stock of an employee stock ownership plan (ESOP), and other dilutive convertible securities.

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The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent, and includes adjustments resulting from the assumption that dilutive convertible securities were converted, options or warrants were exercised, or that other shares were issued upon the satisfaction of certain conditions.

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Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities; of income (loss) available to common shareholders.

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The value of dividends forfeited related to restricted stock awards forfeited.

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Value of preferred stock and warrants for common stock issued.

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Amount of undistributed earnings (loss) allocated to participating securities for the basic earnings (loss) per share or per unit calculation under the two-class method.

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