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Fair Value of Financial Instruments - Additional Information (Details) - USD ($)
$ in Millions
Sep. 30, 2020
Dec. 31, 2019
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying amount of notes payable $ 9.9  
Fair Value Measured Using Net Asset Value | Money Market Funds    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Investments in money market funds $ 19.3 $ 10.3