Quarterly report pursuant to Section 13 or 15(d)

FAIR VALUE OF FINANCIAL INSTRUMENTS - Additional Information (Details)

v3.21.2
FAIR VALUE OF FINANCIAL INSTRUMENTS - Additional Information (Details) - USD ($)
9 Months Ended
Sep. 30, 2021
Mar. 18, 2021
Dec. 31, 2020
RTI warrants      
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Warrants repurchase maximum threshold $ 15,000,000    
Level 3 | Private warrants      
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Dividend yield on warrants 0.00%    
Aggregate value $ 1,316,000 $ 4,604,000  
Level 3 | RTI warrants      
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Dividend yield on warrants 0.00%    
Aggregate value $ 8,214,000   $ 0