Collaboration and License Agreements - Glaxosmithkline Intellectual Property (No. 3) Limited (Details) - USD ($)			3 Months Ended
	Nov. 22, 2021	Oct. 03, 2018	Dec. 31, 2022	Dec. 31, 2021	Sep. 30, 2022
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue			$ 62,546,000	$ 27,439,000
Deferred revenue			66,281,000		$ 74,099,000
Collaboration and License agreements
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Initial transaction price		$ 252,700,000
GSK | Collaboration and License agreements
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone payment	$ 120,000,000
Milestone payment receivable at start of phase two	30,000,000
Milestone payment receivable upon achievement of phase two and first patient dosed in phase three	100,000,000
Initial transaction price	120,000,000
GSK | Collaboration and License agreements | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Commercial milestone payments at first commercial sale	190,000,000
Sales-related milestone payments	$ 590,000,000
GSK | ARO-HSD Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue			0	$ 0
Contract assets			0
Deferred revenue			$ 0