CONVERTIBLE PROMISSORY NOTES - Narrative (Details) - USD ($)		1 Months Ended	6 Months Ended	12 Months Ended
	Aug. 31, 2019	Mar. 31, 2019	Aug. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Short-term Debt [Line Items]
Proceeds from issuance of convertible promissory notes				$ 7,397,000	$ 0
Warrant liability		$ 1,500,000		0	242,000
Derivative liability, fair value		$ 1,400,000
Gain on extinguishment				2,318,000	$ 0
Convertible Promissory Notes
Short-term Debt [Line Items]
Stated rate		12.00%
Debt term		1 year
Conversion price (in usd per share)	$ 7.54	$ 31.05	$ 7.54
Qualified financing threshold		$ 15,000,000.0
Conversion price as percent of price paid per share		80.00%
Share price threshold (in usd per share)		$ 38.82
Proceeds from issuance of convertible promissory notes			$ 7,400,000
Coverage percent		50.00%
Stock issuable upon warrants (in shares)		490,683
Term of warrants		5 years
Exercise price (in usd per share)	$ 42.70	$ 10.36	$ 42.70
Premium percentage on effective price	10.00%
Interest expense				(2,000,000.0)
Accretion of discounts				$ 800,000
Effective rate				12.00%
Gain on extinguishment	$ 2,300,000
Convertible Promissory Notes | Common Stock
Short-term Debt [Line Items]
Shares issued in conversion (in shares)	1,069,740
Officers and Directors | Convertible Promissory Notes
Short-term Debt [Line Items]
Proceeds from issuance of convertible promissory notes			$ 1,700,000