2021 Corporate Restructuring Completion and 2023 Strategic Actions - Corporate Restructuring Completion (Details) $ in Thousands	1 Months Ended				12 Months Ended
	Mar. 31, 2023 ft²	Feb. 28, 2023 Program	Sep. 30, 2022 USD ($)	Sep. 30, 2021	Dec. 31, 2023 USD ($)		Dec. 31, 2022 USD ($)
2021 Corporate Restructuring Completion and 2023 Strategic Actions
Reduction in workforce (as a percent)				75.00%
Restructuring costs			$ 33,000		$ 2,743	[1]	$ 12,838	[1]
Number of programs | Program		2
Percent of Employee Reduction	17
Net cash proceeds from sale of R&D laboratory equipment					1,513		1,866
Research and Development Laboratory Equipment
2021 Corporate Restructuring Completion and 2023 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
2021 Corporate Restructuring Completion and 2023 Strategic Actions
Area of land in sublease | ft²	42,000
Research and development
2021 Corporate Restructuring Completion and 2023 Strategic Actions
Restructuring costs			16,500		2,700		5,900
Selling, general and administrative
2021 Corporate Restructuring Completion and 2023 Strategic Actions
Restructuring costs			16,500				6,900
Severance
2021 Corporate Restructuring Completion and 2023 Strategic Actions
Restructuring costs			33,000
Employee-related separation costs					2,700		12,800
Cash charges related to modification of equity-awards for terminated and remaining employee			17,400		1,200		5,800
Non-cash charges related to modification of equity-awards for terminated and remaining employee			$ 15,600		$ 1,500		$ 7,000

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