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Inventories - Additional Information (Detail) - USD ($)
1 Months Ended 12 Months Ended
Nov. 30, 2019
Dec. 31, 2019
Dec. 31, 2018
Inventory [Line Items]      
Percentage of material received 2.00%    
Write-down of inventory   $ 0 $ 2,212,000
Pre-launch Inventory      
Inventory [Line Items]      
Raw materials inventory   $ 800,000 $ 0