EARNINGS PER SHARE - Narrative (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Options to purchase	4,218,250	3,438,837	4,218,250	3,438,837
Warrants to purchase	8,853,056	7,353,056	8,853,056	7,353,056
Series B Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Convertible preferred stock, common stock issuable upon conversion	3,769,505	3,551,549	3,769,505	3,499,059
Series B1 Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Convertible preferred stock, common stock issuable upon conversion	10,417,966	11,074,331	10,417,966	13,105,989
Series A Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Conversion of stock, shares issued	419,859		419,859	419,859