Quarterly report pursuant to Section 13 or 15(d)

Share-Based Compensation - Additional Information (Details)

Share-Based Compensation - Additional Information (Details) - USD ($)								3 Months Ended		6 Months Ended
	Nov. 24, 2021	Jun. 22, 2021	Jun. 10, 2020	Feb. 14, 2020	Dec. 31, 2018	Dec. 05, 2018	Nov. 18, 2015	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Jun. 23, 2021	Mar. 14, 2018	May 18, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares, Granted										2,286,889
Employee Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unvested employee options outstanding								14,305,867	13,516,250	14,305,867	13,516,250
Expense recognized								$ 1,682,000	$ 277,000	$ 3,363,000	$ 441,000
Unamortized compensation expense share options								18,589,000	23,927,000	$ 18,589,000	$ 23,927,000
Vesting period										2 years 8 months 26 days	3 years 11 months 1 day
Risk-free interest rate based on estimate of U.S. treasury yield										7 years
Restricted Share Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expense recognized								302,000	282,000	$ 516,000	$ 364,000
Number of shares, granted/awarded										792,877
Unamortized stock compensation expense								$ 989,000		$ 989,000
Stock-based compensation expense, expected weighted average period for recognition										1 year 6 months 14 days	1 year 6 months 25 days
Unamortized compensation expense									1,771,000		$ 1,771,000
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]
Expense recognized									$ 0		$ 35,000
Number of shares, granted/awarded								0	0
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 7 months 9 days	3 years 7 months 13 days
Unamortized compensation expense								$ 19,578,000	$ 25,698,000	$ 19,578,000	$ 25,698,000
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
Increase in number of ordinary shares available for issuance							219,605
2018 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares authorized												19,437,298	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]
Number of shares, granted/awarded										792,877
2018 Plan \| Employees and Directors
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares, Granted										2,201,889	13,374,412
2018 Plan \| 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
2018 Plan \| Restricted Share Units (RSUs) \| Employees \| Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period										2 years
2018 Plan \| Restricted Share Units (RSUs) \| Employees \| Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period										4 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	5,000,000
2021 Inducement Plan \| Employees and Directors
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares, Granted										85,000	0
2015 Plan, 2018 Plan and 2021 Inducement Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares, Granted										2,286,889
2015 Plan, 2018 Plan and 2021 Inducement Plan \| Employee Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period										4 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.
Share option granted term										10 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										792,877