SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Fair Value Measurement Inputs (Details)	Sep. 30, 2019	Dec. 31, 2018
Expected term (in years)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value measurement input	10	7.1
Expected volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value measurement input	0.8556	0.3000
Risk free interest rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value measurement input	0.0150	0.0259
Expected dividend yield
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value measurement input	0.0000	0