Fair Value Measurements - Additional Information (Details) - BVF Partners L.P. - USD ($) $ in Millions	3 Months Ended			9 Months Ended	12 Months Ended
	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Sep. 30, 2022	Dec. 31, 2022	Dec. 31, 2021
BVF Agreement
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Non-refundable payments received					$ 15	$ 15
Imputed effective rate of interest on unamortized portion of liability	10.10%	20.60%	20.60%	20.60%
BVF Agreement | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Contingent payments upon achievement of certain clinical and regulatory milestones						73
Gilead Collaboration Agreement | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Contingent payments upon achievement of certain clinical and regulatory milestones						$ 160