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Basis of Presentation and Significant Accounting Policies - Additional Information (Detail) - Segment
 9 Months Ended
Sep. 30, 2020
Dec. 12, 2019
Summary Of Significant Accounting Policies [Line Items]    
Number of operating segments 1  
Change in accounting principle, accounting standards update, adopted true  
Change in accounting principle, accounting standards update, adoption date Jan. 01, 2020  
Change in accounting principle, accounting standards update, immaterial effect true  
Change in accounting principle, type [Extensible List] us-gaap:AccountingStandardsUpdate201613Member  
Casebia Therapeutics Limited Liability Partnership [Member]    
Summary Of Significant Accounting Policies [Line Items]    
Equity method investment, ownership percentage   50.00%