STOCK PLANS (Non-Vested Stock Option Activity) (Details) - Stock options - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Stock Plans
Balance of Nonvested Options (in shares)	374,575	360,444
Options granted	201,881
Vested (in shares)	(187,750)
Nonvested stock options, Weighted Average Fair Value at Grant Date
Balance at beginning of year, weighted average fair value at grant date (in dollars per share)	$ 17.21
Granted, weighted average fair value at grant date (in dollars per share)	17.46	$ 18.97	$ 17.50
Vested, weighted average fair value at grant date (in dollars per share)	16.04
Balance at end of year, weighted average fair value at grant date (in dollars per share)	$ 17.93	$ 17.21