Quarterly report pursuant to Section 13 or 15(d)

FAIR VALUE OF FINANCIAL INSTRUMENTS - Fair Value Measurement Inputs (Details)

v3.21.2
FAIR VALUE OF FINANCIAL INSTRUMENTS - Fair Value Measurement Inputs (Details) - Level 3 - Fair Value Measurements on Recurring Basis
Sep. 30, 2021
Mar. 18, 2021
Expected annual dividend yield | Private warrants    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Warrant, measurement input 0 0
Expected annual dividend yield | RTI warrants    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Warrant, measurement input 0 0
Expected volatility | Private warrants    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Warrant, measurement input 0.562 0.473
Expected volatility | RTI warrants    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Warrant, measurement input 0.5549 0.4851
Risk-free rate of return | Private warrants    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Warrant, measurement input 0.0086 0.0086
Risk-free rate of return | RTI warrants    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Warrant, measurement input 0.0059 0.0054
Expected option term (years) | Private warrants    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Warrant, expected option term (years) 4 years 5 months 19 days 5 years
Expected option term (years) | RTI warrants    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Warrant, expected option term (years) 3 years 3 months 3 years 9 months 14 days