Quarterly report pursuant to Section 13 or 15(d)

Share-Based Compensation - Additional Information (Details)

v3.21.2
Share-Based Compensation - Additional Information (Details) - USD ($)
3 Months Ended 6 Months Ended
Jun. 23, 2021
Jun. 10, 2020
Feb. 14, 2020
Dec. 31, 2018
Dec. 05, 2018
Jun. 30, 2021
Jun. 30, 2020
Jun. 30, 2021
Jun. 30, 2020
Mar. 14, 2018
May 18, 2017
Nov. 18, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                        
Share options granted               13,374,412        
Employee Stock Options                        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                        
Unvested employee options outstanding           13,516,250 550,521 13,516,250 550,521      
Expense recognized           $ 277,000 $ 316,000 $ 441,000 $ 663,000      
Unamortized compensation expense share options           23,927,000 2,336,000 $ 23,927,000 $ 2,336,000      
Vesting period               3 years 11 months 1 day 2 years 1 month 2 days      
Restricted Share Units (RSUs)                        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                        
Expense recognized           282,000 38,000 $ 364,000 $ 62,000      
Number of shares, granted/awarded               1,345,328        
Unamortized stock compensation expense           1,771,000   $ 1,771,000        
Stock-based compensation expense, expected weighted average period for recognition               1 year 6 months 25 days        
Restricted Share Units (RSUs) | Employees and Directors                        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                        
Number of shares, granted/awarded               1,345,328 0      
Restricted Share Units (RSUs) | Director                        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                        
Vesting period               1 year        
Restricted Share Units (RSUs) | Employees                        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                        
Vesting period               2 years        
Performance RSUs                        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                        
Expense recognized           0 832,000 $ 35,000 $ 1,058,000      
Number of shares, granted/awarded               0 1,079,000      
Unamortized stock compensation expense             1,247,000   $ 1,247,000      
Stock-based compensation expense, expected weighted average period for recognition                 5 months 12 days      
Options and Restricted Share Units and Performance Restricted Share Units                        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                        
Vesting period               3 years 7 months 13 days 11 months 26 days      
Unamortized compensation expense           $ 25,698,000 $ 3,583,000 $ 25,698,000 $ 3,583,000      
2015 Plan                        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                        
Number of shares authorized                       223,424
Number of ordinary shares available for issuance                     443,029 219,605
2018 Plan                        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                        
Number of shares authorized                   1,018,459    
Increase in number of ordinary shares available to be granted, percentage     4.00%   4.00%              
Increase in number of ordinary shares available to be granted 15,000,000 2,250,000 594,758 574,081                
2018 Plan | Employees and Directors                        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                        
Share options granted               13,374,412 64,840