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Research Funding Agreement - Additional Information (Details) - USD ($)
3 Months Ended 9 Months Ended
Mar. 06, 2018
Sep. 30, 2019
Sep. 30, 2018
Sep. 30, 2019
Sep. 30, 2018
Research And Development Arrangement Contract To Perform For Others [Line Items]          
Amounts received for qualifying expenses incurred recorded as reduction of research and development expense   $ 500,000   $ 500,000  
Silverstein Foundation | Funding Agreement          
Research And Development Arrangement Contract To Perform For Others [Line Items]          
Upfront sum of funding amount $ 500,000        
Qualifying expenses   $ 0 $ 0 $ 0 $ 0