Annual report pursuant to Section 13 and 15(d)

Share-Based Compensation - Additional Information (Details)

v3.24.1
Share-Based Compensation - Additional Information (Details) - USD ($)
$ / shares in Units, $ in Thousands
 12 Months Ended
Jul. 07, 2022
Nov. 24, 2021
Jun. 22, 2021
Jun. 10, 2020
Feb. 14, 2020
Dec. 31, 2018
Dec. 05, 2018
Nov. 18, 2015
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Jun. 23, 2021
Dec. 31, 2020
Mar. 14, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Number of Shares, Cancelled                   (906,800)        
Cancellation Of Share Option                   $ 17,350        
Share options granted                 857,500 197,085 1,028,090      
Weighted average grant date fair value, options granted                 $ 0.8 $ 2.39 $ 23.67      
Employee Stock Option                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Risk-free interest rate based on estimate of U.S. treasury yield                 7 years          
Employees and Directors                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Expense recognized                 $ 468 $ 3,580 $ 3,779      
Vesting period                 2 years 1 month 2 days 1 year 4 months 28 days 3 years 5 months 26 days      
Share options granted                 857,500 197,085 1,028,090      
Unvested employee options outstanding                 930,010 296,199 1,033,820      
Unamortized compensation expense share options                 $ 1,000 $ 929 $ 21,521      
Restricted Share Units (RSUs)                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Grant date fair value                 $ 7.26 $ 9.87 $ 19.16      
Expense recognized                 $ 316 $ 1,178 $ 960      
Number of shares, granted/awarded                   66,398 123,017      
Unamortized compensation expense                 $ 116 $ 434 $ 1,416      
Stock-based compensation expense, expected weighted average period for recognition                 1 year 11 months 1 day 10 months 17 days 1 year 10 months 20 days      
Restricted Share Units (RSUs) | Employees and Directors                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Number of shares, granted/awarded                 0 66,398 123,017      
Restricted Share Units (RSUs) | Director                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Vesting period                 1 year          
Performance RSUs                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Grant date fair value                         $ 33.18  
Expense recognized                     $ (420)      
Number of shares, granted/awarded                 0 0 0      
Restricted Ordinary Shares, Options and Restricted Share Units and Performance Restricted Share Units                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Vesting period                 2 years 25 days 1 year 3 months 10 days 3 years 3 months 25 days      
Unamortized compensation expense                 $ 1,116 $ 1,363 $ 22,937      
2015 Plan                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Number of shares authorized               14,895            
Number of ordinary shares available for issuance               29,535            
Increase in number of ordinary shares available for issuance               14,640            
2018 Plan                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Number of shares authorized                       1,295,819   67,897
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     1,000,000 150,000 39,650 38,272                
2018 Plan | Restricted Share Units (RSUs) | Employees                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Vesting period                 2 years          
2021 Inducement Plan                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Increase in number of ordinary shares available to be granted   333,333                        
2021 Inducement Plan | Restricted Share Units (RSUs) | Employees                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Vesting period                 4 years          
2015 Plan, 2018 Plan and 2021 Inducement Plan                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Number of Shares, Cancelled                   (906,800)        
Share options granted                 857,500 197,085 1,028,090      
2015 Plan, 2018 Plan and 2021 Inducement Plan | Employee Stock Option                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Share option granted term                 10 years          
Vesting rights                 The vesting requirement is conditioned upon a grantee’s continued service with the Company during the vesting period. Once vested, all awards are exercisable from the date of grant until they expire. The option grants are non-transferable. Vested options generally remain exercisable for 90 days subsequent to the termination of the option holder’s service with the Company. In the event of an option holder’s disability or death while employed by or providing service to the Company, the exercisable period extends to twelve months or eighteen months, respectively.          
2015 Plan, 2018 Plan and 2021 Inducement Plan | Employee Stock Option | Maximum                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Vesting period                 4 years          
2015 Plan, 2018 Plan and 2021 Inducement Plan | Employee Stock Option | Minimum                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Vesting period                 3 years          
2015 Plan, 2018 Plan and 2021 Inducement Plan | Restricted Share Units (RSUs)                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Number of shares, granted/awarded                   66,398 123,017      
Two Thousand Twenty One Inducement Plan                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Share options granted                 2,500 6,332 120,000      
Two Thousand Twenty One Inducement Plan | Restricted Share Units (RSUs)                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Number of shares, granted/awarded                     33,333      
Amended And Restated 2018 Equity Incentive Plan [Member]                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Number of Shares, Cancelled 906,800                          
Amended And Restated 2018 Equity Incentive Plan [Member] | Employee Stock Option                            
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]                            
Cancellation Of Share Option                   $ 17,350