Balance Sheet Accounts - Narrative (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2025	Mar. 31, 2024
Property, Plant and Equipment [Line Items]
Depreciation and amortization expense for property and equipment	$ 5.6	$ 4.1		$ 10.4	$ 7.9
Buildings
Property, Plant and Equipment [Line Items]
Property, plant and equipment, reclassification			$ 76.0	172.9
Construction In Progress Reclassified To Building
Property, Plant and Equipment [Line Items]
Property, plant and equipment, reclassification				(172.9)
Manufacturing equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, reclassification				$ 13.8
Manufacturing equipment | Minimum
Property, Plant and Equipment [Line Items]
Useful life	7 years			7 years
Manufacturing equipment | Maximum
Property, Plant and Equipment [Line Items]
Useful life	10 years			10 years
Construction In Progress Reclassified To Manufacturing Equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, reclassification				$ (13.8)
Manufacturing Facility
Property, Plant and Equipment [Line Items]
Useful life	39 years			39 years
Construction in progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, reclassification			$ (76.0)