Quarterly report pursuant to Section 13 or 15(d)

FAIR VALUE OF FINANCIAL INSTRUMENTS - Summary of Liabilities Measurements on a Recurring Basis (Details)

v3.21.2
FAIR VALUE OF FINANCIAL INSTRUMENTS - Summary of Liabilities Measurements on a Recurring Basis (Details) - USD ($)
Sep. 30, 2021
Dec. 31, 2020
Assets    
Investments $ 184,575,000 $ 0
Commercial paper, available for sale    
Assets    
Investments 83,723,000 0
Corporate Bonds, available for sale    
Assets    
Investments 94,974,000 0
Municipal bonds, available for sale    
Assets    
Investments 5,878,000 0
Fair Value Measurements on Recurring Basis    
Assets    
Total investments 184,575,000 0
Liabilities    
Total warrant liability 9,530,000 0
Fair Value Measurements on Recurring Basis | RTI warrants    
Liabilities    
Warrant liability 8,214,000 0
Fair Value Measurements on Recurring Basis | Private warrants    
Liabilities    
Warrant liability 1,316,000 0
Fair Value Measurements on Recurring Basis | Commercial paper, available for sale    
Assets    
Investments 83,723,000 0
Fair Value Measurements on Recurring Basis | Corporate Bonds, available for sale    
Assets    
Investments 94,974,000 0
Fair Value Measurements on Recurring Basis | Municipal bonds, available for sale    
Assets    
Investments 5,878,000 0
Fair Value Measurements on Recurring Basis | Level 1    
Assets    
Total investments 0 0
Liabilities    
Total warrant liability 0 0
Fair Value Measurements on Recurring Basis | Level 1 | RTI warrants    
Liabilities    
Warrant liability 0 0
Fair Value Measurements on Recurring Basis | Level 1 | Private warrants    
Liabilities    
Warrant liability 0 0
Fair Value Measurements on Recurring Basis | Level 1 | Commercial paper, available for sale    
Assets    
Investments 0 0
Fair Value Measurements on Recurring Basis | Level 1 | Corporate Bonds, available for sale    
Assets    
Investments 0 0
Fair Value Measurements on Recurring Basis | Level 1 | Municipal bonds, available for sale    
Assets    
Investments 0 0
Fair Value Measurements on Recurring Basis | Level 2    
Assets    
Total investments 184,575,000 0
Liabilities    
Total warrant liability 0 0
Fair Value Measurements on Recurring Basis | Level 2 | RTI warrants    
Liabilities    
Warrant liability 0 0
Fair Value Measurements on Recurring Basis | Level 2 | Private warrants    
Liabilities    
Warrant liability 0 0
Fair Value Measurements on Recurring Basis | Level 2 | Commercial paper, available for sale    
Assets    
Investments 83,723,000 0
Fair Value Measurements on Recurring Basis | Level 2 | Corporate Bonds, available for sale    
Assets    
Investments 94,974,000 0
Fair Value Measurements on Recurring Basis | Level 2 | Municipal bonds, available for sale    
Assets    
Investments 5,878,000 0
Fair Value Measurements on Recurring Basis | Level 3    
Assets    
Total investments 0 0
Liabilities    
Total warrant liability 9,530,000 0
Fair Value Measurements on Recurring Basis | Level 3 | RTI warrants    
Liabilities    
Warrant liability 8,214,000 0
Fair Value Measurements on Recurring Basis | Level 3 | Private warrants    
Liabilities    
Warrant liability 1,316,000 0
Fair Value Measurements on Recurring Basis | Level 3 | Commercial paper, available for sale    
Assets    
Investments 0 0
Fair Value Measurements on Recurring Basis | Level 3 | Corporate Bonds, available for sale    
Assets    
Investments 0 0
Fair Value Measurements on Recurring Basis | Level 3 | Municipal bonds, available for sale    
Assets    
Investments $ 0 $ 0