STOCKHOLDERS' EQUITY - Restricted stock unit (Details) - Restricted stock	9 Months Ended
	Sep. 30, 2020 USD ($) shares
Restricted Stock Units, Beginning Balance	2,086,750
Restricted Stock Units, Intrinsic Value Beginning Balance | $	$ 8,033,988
Restricted Stock Units, Granted	278,700
Restricted Stock Units, Forfeited	(25,250)
Restricted Stock Units, Ending Balance	2,340,200
Restricted Stock Units, Intrinsic Value Ending Balance | $	$ 18,663,095
Board of Directors
Restricted Stock Units, Beginning Balance	277,200
Restricted Stock Units, Granted	0
Restricted Stock Units, Forfeited	0
Restricted Stock Units, Ending Balance	277,200
Executive Management
Restricted Stock Units, Beginning Balance	604,500
Restricted Stock Units, Granted	120,000
Restricted Stock Units, Forfeited	0
Restricted Stock Units, Ending Balance	724,500
Other Employees
Restricted Stock Units, Beginning Balance	1,205,050
Restricted Stock Units, Granted	158,700
Restricted Stock Units, Forfeited	(25,250)
Restricted Stock Units, Ending Balance	1,338,500