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Stock-based Compensation - Additional Information (Detail)
$ in Millions
9 Months Ended
Sep. 30, 2020
USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Total unrecognized compensation expense related to stock options $ 105.5
Stock Options [Member]  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Unrecognized compensation expense, remaining weighted-average period for recognition 2 years 7 months 6 days
Restricted Common Shares [Member]  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Unrecognized compensation expense, remaining weighted-average period for recognition 2 years
Total unrecognized compensation expense $ 31.6