Collaboration and License Agreements - Horizon Therapeutics Ireland DAC (Details) $ in Thousands		1 Months Ended	3 Months Ended	12 Months Ended
	Jun. 18, 2021 obligation bundle	Jul. 31, 2021 USD ($)	Mar. 31, 2023 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenues				$ 240,735	$ 243,231	$ 138,287
Horizon | Horizon License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Number of distinct performance obligations | obligation	1
Number of distinct bundle | bundle	1
Initial transaction price		$ 40,000
Upfront milestone payment received			$ 15,000
Revenues				$ 1,500	$ 2,500