PREFERRED STOCK AND TEMPORARY EQUITY - Series B1 Preferred Stock and Temporary Equity Narrative (Details)				1 Months Ended	12 Months Ended
	May 10, 2016 USD ($) shares warrant $ / shares	Jun. 30, 2015 $ / shares	Jun. 24, 2015 USD ($) shares warrant $ / shares	May 31, 2016 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) $ / shares	Jun. 24, 2020 $ / shares	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Jun. 24, 2017 $ / shares	May 13, 2016 $ / shares
Class of Stock [Line Items]
Number of units sold (in shares) | shares	12,403,683		8,064,534
Unit Purchase Agreement, number of warrants per unit | warrant	1
Unit Purchase Agreement, price per unit (in dollars per share)	$ 1.56		$ 3.10
Unit Purchase Agreement, exercise price (in dollars per share)	2.60%		6.10%
Share price (in dollars per unit)	$ 1.52		$ 2.91
Gross proceeds from issuance of private placement | $	$ 19,400,000		$ 25,000,000.0
Commission percentage of gross proceeds			6.50%	6.50%
Commissions payment | $			$ 1,400,000	$ 610,000
Unit Purchase Agreement, liquidated damages, percentage of aggregate subscription amount			1.00%	1.00%
Unit Purchase Agreement, maximum percentage of liquidated damages to aggregate subscription amount			6.00%	6.00%
Derivative warrant liability | $					$ 1,969,216		$ 1,481,692
Series B and B1 preferred shares | $					$ 28,146,347		22,179,963
Beneficial conversion feature | $			$ 5,737,796
Private placement fees | $			$ 1,400,000
Series B1 Preferred Stock
Class of Stock [Line Items]
Preferred stock, dividend rate				6.00%
Preferred stock, dividends in arrears (in dollars per share)				$ 1.56
Minimum dividend payment price (in dollars per share)				1.52
Dividends payable, paid-in-kind (in dollars per share)				1.56
Liquidation preference per share (in dollars per share)				1.56
Convertible preferred stock, conversion terms, threshold closing price (in dollars per share)				$ 1.56
Convertible preferred stock, conversion ratio				1
Conversion terms, closing price (in dollars per share)				$ 3.90
Conversion terms, threshold consecutive trading days				20 days
Redemption price per share (in dollars per share)									$ 1.72	$ 1.33
Conversion terms, beneficial ownership limitation (as a percent)					4.999%
Unit Purchase Agreement, number of shares per unit (in shares) | shares	1
Share price (in dollars per unit)										$ 1.52
Series B and B1 preferred shares | $					$ 12,743,047		13,279,755	$ 15,769,478
Beneficial conversion feature | $				$ 2,371,106
Private placement fees | $				$ 600,000
Dividends payable | $					$ 211,256		235,360
Series B Preferred Stock
Class of Stock [Line Items]
Preferred stock, dividend rate					6.00%
Preferred stock, dividends in arrears (in dollars per share)					$ 3.10
Minimum dividend payment price (in dollars per share)		$ 2.91
Dividends payable, paid-in-kind (in dollars per share)					3.10
Liquidation preference per share (in dollars per share)					3.10
Conversion terms, closing price (in dollars per share)					$ 6.20
Conversion terms, threshold consecutive trading days					20 days
Redemption price per share (in dollars per share)			$ 2.23		$ 3.10
Conversion terms, beneficial ownership limitation (as a percent)					9.999%
Unit Purchase Agreement, number of shares per unit (in shares) | shares			1
Share price (in dollars per unit)			$ 2.94
Unit Purchase Agreement, percentage of proceeds used to repurchase stock				60.00%
Payments for repurchase of preferred stock | $				$ 11,189,838
Stock repurchased and retired during period, (in shares) | shares				3,575,070
Series B and B1 preferred shares | $					$ 11,006,406		8,900,208	$ 7,190,467
Dividends payable | $					$ 177,921		$ 167,642
Forecast | Series B1 Preferred Stock
Class of Stock [Line Items]
Redemption price per share (in dollars per share)						$ 1.56
Maximum | Series B1 Preferred Stock
Class of Stock [Line Items]
Conversion terms, beneficial ownership limitation (as a percent)					9.999%
Previous Participating Investors | Series B Preferred Stock
Class of Stock [Line Items]
Gross proceeds from issuance of private placement | $				$ 18,649,738
Net proceeds from issuance of private placement before agent fees and offering costs | $				8,200,000
Warrant
Class of Stock [Line Items]
Unit Purchase Agreement, number of warrants per unit | warrant			1
Number of shares called by each warrant (in shares) | shares	0.25		0.5
Exercise price of warrants (in dollars per share)	$ 1.53		$ 2.92
Amount over closing price of warrant exercise price (in dollars per share)	$ 0.01		$ 0.01
Warrant | Series B1 Preferred Stock
Class of Stock [Line Items]
Derivative warrant liability | $				$ 2,867,264