Leases - Narrative (Details) ft² in Thousands, $ in Millions	3 Months Ended
	Dec. 31, 2023 USD ($) ft² option	Dec. 31, 2022 USD ($)	Sep. 25, 2023 USD ($)
Lessee Lease Description [Line Items]
Short-term lease cost | $	$ 0.0	$ 0.1
Corporate Headquarters In Pasadena | California
Lessee Lease Description [Line Items]
Office space leases (in sq ft) | ft²	49
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 San Diego | California
Lessee Lease Description [Line Items]
Office space leases (in sq ft) | ft²	144
Operating lease renewal term	10 years
Lease term	15 years
Maximum additional tenant improvement allowance | $	$ 7.2		$ 23.6
Additional tenant improvement allowance interest per annum	7.00%		9.00%
Additional tenant improvement allowance liability | $	$ 30.8
Research Facility in San Diego | California | Maximum
Lessee Lease Description [Line Items]
Number of options to renew | option	1
Research Facility in Madison | Wisconsin
Lessee Lease Description [Line Items]
Office space leases (in sq ft) | ft²	115
Number of options to renew | option	2
Operating lease renewal term	5 years