FAIR VALUE MEASUREMENTS - SCHEDULE OF FINANCIAL INSTRUMENTS MEASURED AT FAIR VALUE ON RECURRING BASIS (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash held in banks	$ 36,654	$ 13,908
Fair value, measurements, recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets at fair value	70,620	45,614
Fair value, measurements, recurring | Money market accounts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market accounts	70,620	45,614
Fair value, measurements, recurring | Quoted Prices  in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets at fair value	70,620	45,614
Fair value, measurements, recurring | Quoted Prices  in Active Markets for Identical Assets (Level 1) | Money market accounts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market accounts	70,620	45,614
Fair value, measurements, recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets at fair value	0	0
Fair value, measurements, recurring | Significant Other Observable Inputs (Level 2) | Money market accounts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market accounts	0	0
Fair value, measurements, recurring | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets at fair value	0	0
Fair value, measurements, recurring | Significant Unobservable Inputs (Level 3) | Money market accounts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market accounts	$ 0	$ 0