STOCK PLANS, Stock Options (Details) - Stock Options [Member] - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Stock options, number of shares [Roll Forward]
Balance, beginning of period (in shares)	607,631
Granted (in shares)	0
Expired (in shares)	0
Cancelled / Forfeited (in shares)	0
Exercised (in shares)	(9,684)
Balance, end of period (in shares)	597,947
Exercisable (vested) at end of period (in shares)	394,704
Stock options, weighted average exercise price [Roll Forward]
Balance, beginning of period (in dollars per share)	$ 8.91
Granted (in dollars per share)	0
Expired (in dollars per share)	0
Cancelled / Forfeited (in dollars per share)	0
Exercised (in dollars per share)	3.31
Balance, end of period (in dollars per share)	9.01
Exercisable (vested) at end of period (in dollars per share)	$ 8.21
Stock options, additional disclosures [Abstract]
Outstanding, aggregate intrinsic value	$ 1,008,507
Exercisable (vested), aggregate intrinsic value	$ 977,478
Outstanding, weighted average remaining contractual term	6 years 6 months 29 days
Exercisable (vested), weighted average remaining contractual term	5 years 7 months 9 days
Intrinsic value of options exercised	$ 63,000	$ 96,000
Fair value of awards vested	182,000	$ 149,000
Unrecognized compensation related to non-vested stock options	$ 280,000
Unrecognized compensation cost, period for recognition	2 years 3 months 3 days
Recognized compensation cost	$ 40,000