SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Summary of Fair Value Hierarchy of Financial Liabilities Measured at Fair Value (Details) - Fair Value, Measurements, Recurring - USD ($)
Jun. 30, 2020
Dec. 31, 2019
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Derivative liability $ 247,000 $ 408,000
Warrant liabilities 0 2,637,500
Total liabilities at fair value 247,000 3,045,500
Quoted Prices in Active Markets for Identical Assets (Level 1)    
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Derivative liability 0 0
Warrant liabilities 0 0
Total liabilities at fair value 0 0
Significant Other Observable Inputs (Level 2)    
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Derivative liability 0 0
Warrant liabilities 0 0
Total liabilities at fair value 0 0
Significant Unobservable Inputs (Level 3)    
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Derivative liability 247,000 408,000
Warrant liabilities 0 2,637,500
Total liabilities at fair value $ 247,000 $ 3,045,500