INCOME TAXES - Uncertain Tax Positions (Details) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
INCOME TAXES
Uncertain tax liabilities, beginning of period	$ 101,789	$ 101,789
Settlements with tax authority during current year	(101,789)	0
Uncertain tax liabilities, end of period	$ 0	$ 101,789