FAIR VALUE MEASUREMENTS - Level 3 Fair Value Measurements Inputs (Details) - Level 3	Jun. 30, 2021 $ / shares	Dec. 31, 2020 $ / shares
Stock price
FAIR VALUE MEASUREMENTS
Measurement input	9.93	9.54
Strike price
FAIR VALUE MEASUREMENTS
Measurement input	11.50	11.50
Volatility
FAIR VALUE MEASUREMENTS
Measurement input	35.6	17.5
Risk-free rate
FAIR VALUE MEASUREMENTS
Measurement input	0.84	0.41
Dividend yield
FAIR VALUE MEASUREMENTS
Measurement input	0.0	0.0
Fair value of warrants
FAIR VALUE MEASUREMENTS
Measurement input	2.64	0.94