STOCK OPTIONS - STOCK COMPENSATION - Stock options outstanding and exercisable (Details)	12 Months Ended
	Dec. 31, 2020 $ / shares shares
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number outstanding | shares	200,878
Options Outstanding Weighted Average Remaining Contractual Life (Years)	4 years 1 month 6 days
Weighted Average Exercise Price (in dollars per share) | $ / shares	$ 6.59
Number exercisable | shares	195,544
Options Exercisable Weighted Average Remaining Contractual Life (Years)	4 years
Weighted Average Exercise Price (in dollars per share) | $ / shares	$ 6.54
Exercise Price Range One [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number outstanding | shares	16,199
Options Outstanding Weighted Average Remaining Contractual Life (Years)	4 months 24 days
Weighted Average Exercise Price (in dollars per share) | $ / shares	$ 4.37
Number exercisable | shares	16,199
Options Exercisable Weighted Average Remaining Contractual Life (Years)	4 months 24 days
Weighted Average Exercise Price (in dollars per share) | $ / shares	$ 4.37
Exercise Price Range Two [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number outstanding | shares	2,090
Options Outstanding Weighted Average Remaining Contractual Life (Years)	1 year 4 months 24 days
Weighted Average Exercise Price (in dollars per share) | $ / shares	$ 4.29
Number exercisable | shares	2,090
Options Exercisable Weighted Average Remaining Contractual Life (Years)	1 year 4 months 24 days
Weighted Average Exercise Price (in dollars per share) | $ / shares	$ 4.29
Exercise Price Range Three [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number outstanding | shares	41,809
Options Outstanding Weighted Average Remaining Contractual Life (Years)	1 year 6 months
Weighted Average Exercise Price (in dollars per share) | $ / shares	$ 4.74
Number exercisable | shares	41,809
Options Exercisable Weighted Average Remaining Contractual Life (Years)	1 year 6 months
Weighted Average Exercise Price (in dollars per share) | $ / shares	$ 4.74
Exercise Price Range Four [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number outstanding | shares	47,030
Options Outstanding Weighted Average Remaining Contractual Life (Years)	2 years 3 months 18 days
Weighted Average Exercise Price (in dollars per share) | $ / shares	$ 7.86
Number exercisable | shares	47,030
Options Exercisable Weighted Average Remaining Contractual Life (Years)	2 years 3 months 18 days
Weighted Average Exercise Price (in dollars per share) | $ / shares	$ 7.86
Exercise Price Range Five [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number outstanding | shares	85,750
Options Outstanding Weighted Average Remaining Contractual Life (Years)	6 years 8 months 12 days
Weighted Average Exercise Price (in dollars per share) | $ / shares	$ 7.09
Number exercisable | shares	85,750
Options Exercisable Weighted Average Remaining Contractual Life (Years)	6 years 8 months 12 days
Weighted Average Exercise Price (in dollars per share) | $ / shares	$ 7.09
Exercise Price Range Six [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number outstanding | shares	8,000
Options Outstanding Weighted Average Remaining Contractual Life (Years)	8 years 2 months 12 days
Weighted Average Exercise Price (in dollars per share) | $ / shares	$ 8.55
Number exercisable | shares	2,666
Options Exercisable Weighted Average Remaining Contractual Life (Years)	8 years 2 months 12 days
Weighted Average Exercise Price (in dollars per share) | $ / shares	$ 8.55