Leases - Narrative (Details) $ in Thousands		3 Months Ended		6 Months Ended
	Nov. 19, 2021 USD ($) ft² option	Mar. 31, 2023 USD ($) ft² option	Mar. 31, 2022 USD ($)	Mar. 31, 2023 USD ($) ft² option	Mar. 31, 2022 USD ($)	Dec. 23, 2022	Sep. 30, 2019 option
Lessee Lease Description [Line Items]
Estimated lease payments		$ 149,212		$ 149,212
Short-term lease cost		$ 400	$ 300	$ 700	$ 500
Research Facility in San Diego | California
Lessee Lease Description [Line Items]
Lease term	15 years
Office space leases (in sq ft) | ft²	144,000
Estimated lease payments	$ 119,000
Estimated payments for operating expenses	3,000
Payments for leasehold improvements, net of tenant improvement allowances	$ 32,000
Operating lease renewal term	10 years
Research Facility in San Diego | California | Sorrento Valley Owner (DE) LLC
Lessee Lease Description [Line Items]
Lease term						6 months
Research Facility in San Diego | California | Maximum
Lessee Lease Description [Line Items]
Number of options to renew | option	1
Corporate Headquarters In Pasadena | California
Lessee Lease Description [Line Items]
Office space leases (in sq ft) | ft²	49,000
Corporate Headquarters In Pasadena | California | Colorado Owner, LLC
Lessee Lease Description [Line Items]
Number of options to renew | option							1
Operating lease renewal term							5 years
Research Facility in Madison | Wisconsin
Lessee Lease Description [Line Items]
Office space leases (in sq ft) | ft²		111,000		111,000
Number of options to renew | option		2		2
Operating lease renewal term		5 years		5 years