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Long-Term Debt - Schedule of Future Principal Payments and the Final Payments Due (Detail) - USD ($)
$ in Thousands
Sep. 30, 2020
Dec. 31, 2019
Debt Disclosure [Abstract]    
2020 $ 0  
2021 0  
2022 14,871  
2022 10,129  
Principal amount of long-term debt $ 25,000 $ 20,000