Strategic Actions (Details) $ / shares in Units, shares in Thousands, $ in Thousands			1 Months Ended			3 Months Ended		6 Months Ended
		Feb. 27, 2023 USD ($)	Jul. 31, 2023 USD ($) $ / shares shares	Jun. 30, 2023 USD ($) shares	Mar. 31, 2023 ft²	Jun. 30, 2023 USD ($) $ / shares shares	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($) $ / shares shares	Jun. 30, 2022 USD ($)	Sep. 30, 2022 USD ($)
Strategic Actions
Share repurchase authorized amount		$ 75,000
Share repurchase authorized amount				$ 325,000		$ 325,000		$ 325,000		$ 250,000
Consideration for repurchase								$ 135,896
Share price (in dollars per share) | $ / shares						$ 11.05		$ 10.90
Aggregate costs						$ 80,500		$ 135,600
Repurchase of ordinary shares (in shares) | shares				263,800		7,280		12,440
Remaining repurchase amount				$ 61,200		$ 61,200		$ 61,200
Percent of Employee Reduction					17
Restructuring costs	[1]					1,169	$ 3,005	2,743	$ 12,329
Net cash proceeds from sale of R&D laboratory equipment								1,513	1,866
Research and Development Laboratory Equipment
Strategic Actions
R&D laboratory equipment carrying value								2,700
Net cash proceeds from sale of R&D laboratory equipment								1,500
Office and Laboratory Space, South San Francisco
Strategic Actions
Area of land in sublease | ft²					42,000
Severance
Strategic Actions
Employee-related separation costs						1,200		2,700	12,300
Cash charges related to modification of equity-awards for terminated and remaining employee								1,200	6,000
Non-cash charges related to modification of equity-awards for terminated and remaining employee								1,500	6,300
Selling, general and administrative
Strategic Actions
Restructuring costs							2,000		6,600
Research and development
Strategic Actions
Restructuring costs						$ 1,200	$ 1,000	$ 2,700	$ 5,700
Subsequent Event [Member]
Strategic Actions
Share price (in dollars per share) | $ / shares			$ 9.88
Repurchase of ordinary shares (in shares) | shares			10,300
Remaining repurchase amount			$ 50,900

[1] Amounts include share-based compensation expense as follows: