SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Summary of Valuation Input for Warrant and Derivative Liabilities (Details)	Dec. 31, 2019 $ / shares year	Dec. 25, 2019 $ / shares year	Sep. 30, 2019 month	May 17, 2019 $ / shares year	May 01, 2019 $ / shares year	Mar. 18, 2019 $ / shares year	Mar. 08, 2019 month $ / shares	Dec. 31, 2018 month $ / shares	Jan. 29, 2018
Expected dividend yield
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative liability, measurement inputs	0.000						0.000	0.000
Warrants, measurement input									0
Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative liability, measurement inputs	0.291						0.293	0.136
Expected stock price volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative liability, measurement inputs	0.960						1.011	1.056
Warrants, measurement input									0.848
Risk-free interest rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative liability, measurement inputs	0.016						0.025	0.025
Warrants, measurement input									0.025
Expected term
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative liability, measurement inputs | month			14				24	21
Price of the underlying common stock (in dollars per share)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative liability, measurement inputs	0.56						1.99	2.31
Short-Term Warrants | Conversion price (in dollars per share)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants, measurement input	4.00					4.00
Short-Term Warrants | Expected stock price volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants, measurement input	0.976					1.220
Short-Term Warrants | Risk-free interest rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants, measurement input	0.015					0.025
Short-Term Warrants | Expected term
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants, measurement input | year	0.25					1
Short-Term Warrants | Price of the underlying common stock (in dollars per share)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants, measurement input	0.56					2.48
Long-Term Warrants | Conversion price (in dollars per share)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants, measurement input				2.13		2.56
Long-Term Warrants | Expected stock price volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants, measurement input				0.834		0.852
Long-Term Warrants | Risk-free interest rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants, measurement input	0.017			0.022		0.022
Long-Term Warrants | Expected term
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants, measurement input | year						5
Long-Term Warrants | Price of the underlying common stock (in dollars per share)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants, measurement input	0.56			1.58		2.48
Exchange Warrants | Expected stock price volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants, measurement input					0.841
Exchange Warrants | Risk-free interest rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants, measurement input		0.017			0.022
Exchange Warrants | Price of the underlying common stock (in dollars per share)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants, measurement input		0.56			1.54
Minimum | Long-Term Warrants | Conversion price (in dollars per share)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants, measurement input	2.13
Minimum | Long-Term Warrants | Expected stock price volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants, measurement input	0.873
Minimum | Long-Term Warrants | Expected term
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants, measurement input | year	4.2			5
Minimum | Exchange Warrants | Conversion price (in dollars per share)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants, measurement input		2.13			2.13
Minimum | Exchange Warrants | Expected stock price volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants, measurement input		0.873
Minimum | Exchange Warrants | Expected term
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants, measurement input | year		4.4			5
Maximum | Long-Term Warrants | Conversion price (in dollars per share)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants, measurement input	2.56
Maximum | Long-Term Warrants | Expected stock price volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants, measurement input	0.893
Maximum | Long-Term Warrants | Expected term
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants, measurement input | year	4.3
Maximum | Exchange Warrants | Conversion price (in dollars per share)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants, measurement input		2.53			2.53
Maximum | Exchange Warrants | Expected stock price volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants, measurement input		0.889
Maximum | Exchange Warrants | Expected term
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants, measurement input | year		4.9			5.5