v3.20.1
License Agreement - Additional Information (Detail) - USD ($)
3 Months Ended 12 Months Ended
Jun. 28, 2018
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Dec. 31, 2019
Dec. 31, 2018
License Agreement [Line Items]            
Cash received from license agreement $ 20,000,000          
License revenue   $ 2,144 $ 18,821,953 $ 1,333,333   $ 20,157,430
License [Member]            
License Agreement [Line Items]            
License revenue         $ 20,000,000