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Stock Incentive Plans and Stock-Based Compensation - Additional Information (Detail)
6 Months Ended 12 Months Ended
Nov. 30, 2021
$ / shares
shares
May 31, 2021
$ / shares
shares
Nov. 30, 2020
$ / shares
shares
May 31, 2020
$ / shares
shares
Nov. 30, 2019
$ / shares
shares
May 31, 2019
$ / shares
shares
Dec. 31, 2021
USD ($)
$ / shares
Dec. 31, 2020
USD ($)
$ / shares
Dec. 31, 2019
USD ($)
$ / shares
Dec. 31, 2021
£ / shares
Dec. 31, 2021
USD ($)
shares
Dec. 31, 2020
£ / shares
Mar. 31, 2015
£ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                          
Common stock, par value | £ / shares                   £ 0.50   £ 0.50 £ 0.50
Weighted average fair value of the stock options granted | $ / shares             $ 5.12 $ 14.43 $ 17.07        
Grant date fair value of options vested             $ 21,100,000 $ 22,500,000 $ 14,500,000        
Proceeds from the exercise of options             2,921,000 5,158,000 24,478,000        
Intrinsic value of options exercised             $ 4,900,000 9,000,000.0 90,500,000        
Unrecognized stock-based compensation expense related to unvested stock option                     $ 30,700,000    
Unrecognized stock-based compensation expense related to unvested stock option, recognition period             2 years 2 months 12 days            
Compensation expense related to stock option             $ 23,000,000.0 22,400,000 16,300,000        
Compensation expense in relation to restricted stock units             $ 13,900,000 $ 23,400,000 $ 14,600,000        
Ordinary shares, reserved and available for issuance | shares                     13,229,000    
Stock Options                          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                          
Employee Stock options, Vesting Period             4 years            
Stock Incentive Plan 2020                          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                          
Number of shares | shares                     20,000,000    
Plans | Stock Options                          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                          
Employee Stock options, Vesting Period             4 years            
Expire period             10 years            
2017 Employee Stock Purchase Plan                          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                          
Ordinary shares, reserved and available for issuance | shares                     3,000,000    
Percentage of fair market value to payroll deductions to eligible employees to purchase ordinary shares             85.00%            
Maximum fair market value of stock which can be purchased by participant in calendar year             $ 25,000            
Issuance of common stock under employee stock purchase plan (in shares) | shares 172,884 226,402 223,545 123,608 75,673 47,358              
Sale of stock price per share | $ / shares $ 3.06 $ 3.86 $ 4.22 $ 5.83 $ 14.92 $ 15.02              
Reserved for future issuance | shares                     1,818,273    
2017 Employee Stock Purchase Plan | Maximum                          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                          
Percentage of payroll deductions to eligible employees to purchase ordinary shares                     15.00%