FAIR VALUE MEASUREMENTS, Level 3 Fair Value Measurement Inputs (Details)	Jun. 30, 2021 USD ($)	Dec. 31, 2020 USD ($)
Fair Value Measurements [Abstract]
Expected life of the options to convert	5 years
Private Placement Warrants [Member]
Fair Value Measurements [Abstract]
Expected life of the options to convert	5 years 8 months 12 days	5 years 11 months 12 days
Private Placement Warrants [Member] | Common Stock Price [Member]
Fair Value Measurements [Abstract]
Measurement input	10.03	9.77
Private Placement Warrants [Member] | Volatility [Member]
Fair Value Measurements [Abstract]
Measurement input	0.1620	0.2259
Private Placement Warrants [Member] | Risk-Free Rate [Member]
Fair Value Measurements [Abstract]
Measurement input	0.0099	0.0050
Private Placement Warrants [Member] | Dividend Yield [Member]
Fair Value Measurements [Abstract]
Measurement input	0	0
FPA liability - Committed [Member]
Fair Value Measurements [Abstract]
Expected life of the options to convert	8 months 12 days	11 months 12 days
FPA liability - Committed [Member] | Common Stock Price [Member]
Fair Value Measurements [Abstract]
Measurement input	10.03	9.77
FPA liability - Committed [Member] | Risk-Free Rate [Member]
Fair Value Measurements [Abstract]
Measurement input	0.0006	0.0010
FPA liability - Optional [Member]
Fair Value Measurements [Abstract]
Expected life of the options to convert	8 months 12 days	11 months 12 days
FPA liability - Optional [Member] | Common Stock Price [Member]
Fair Value Measurements [Abstract]
Measurement input	10.03	9.77
FPA liability - Optional [Member] | Volatility [Member]
Fair Value Measurements [Abstract]
Measurement input	0.10	0.10
FPA liability - Optional [Member] | Risk-Free Rate [Member]
Fair Value Measurements [Abstract]
Measurement input	0.0006	0.0010