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STOCK-BASED COMPENSATION - Summary of Stock options exercised, restricted stock vested, shares withheld and shares issued (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Number of Shares
Stock compensation expense	$ 582,000	$ 608,000	$ 1,700,000	$ 1,700,000
Unrecognized compensation expense	$ 4,100,000		$ 4,100,000
Weighted average period			2 years 2 months 12 days
Stock options
Number of Shares
Stock Options, Exercised/Vested			2,524	15,244
Stock Options, Shares withheld				(2,318)
Stock Options, Shares Issued			2,524	12,926
Non-performance based restricted stock
Number of Shares
Restricted Stock, Exercised/Vested			14,811	3,100
Restricted Stock, Shares withheld			(1,761)	(658)
Restricted Stock, Shares Issued			$ 13,050	$ 2,442