Property, Plant and Equipment - Schedule of Property, Plant and Equipment (Details) - USD ($) $ in Millions	Mar. 31, 2021	Sep. 30, 2020
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 1,408.3	$ 1,397.0
Less accumulated depreciation	(847.1)	(831.1)
Property, plant and equipment, net	561.2	565.9
Land and Land Improvements
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	65.6	63.9
Buildings
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	387.6	377.1
Machinery and Equipment
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	711.3	723.7
Software and Related Costs
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	182.6	175.6
Equipment on Operating Lease to Others
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	19.6	21.7
Construction in Progress
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 41.6	$ 35.0