Supplemental Balance Sheet Information - Property, Plant, and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022
Property, Plant, and Equipment
Property, plant and equipment, gross	$ 1,450.4	$ 1,233.8
Accumulated depreciation	(491.7)	(415.5)
Property, plant and equipment, net	958.7	818.3
Accumulated depreciation	(67.4)	(50.0)
Net finance lease assets	261.7	240.0
Depreciation	89.2	72.0	$ 54.7
Land
Property, Plant, and Equipment
Property, plant and equipment, gross	160.1	148.5
Total finance lease assets	96.1	85.4
Buildings
Property, Plant, and Equipment
Property, plant and equipment, gross	869.5	725.1
Total finance lease assets	165.6	154.6
Machinery and equipment
Property, Plant, and Equipment
Property, plant and equipment, gross	348.7	302.6
Construction in progress
Property, Plant, and Equipment
Property, plant and equipment, gross	72.1	57.6
Assets held under capital and finance leases
Property, Plant, and Equipment
Total finance lease assets	261.7	240.0
Accumulated depreciation	(67.4)	(50.0)
Net finance lease assets	$ 194.3	$ 190.0