Property, Plant and Equipment (Details) - USD ($) $ in Millions	Jun. 30, 2026	Mar. 31, 2026
Property, Plant and Equipment
Property, plant and equipment, Gross	$ 1,446.8	$ 1,422.6
Less: accumulated depreciation	(910.7)	(901.7)
Net property, plant and equipment	536.1	520.9
Land
Property, Plant and Equipment
Property, plant and equipment, Gross	18.9	19.1
Buildings and improvements
Property, Plant and Equipment
Property, plant and equipment, Gross	$ 298.8	291.1
Buildings and improvements \| Minimum
Property, Plant and Equipment
Property, plant and equipment, Useful life	10 years
Buildings and improvements \| Maximum
Property, Plant and Equipment
Property, plant and equipment, Useful life	40 years
Machinery and equipment
Property, Plant and Equipment
Property, plant and equipment, Gross	$ 914.6	904.1
Machinery and equipment \| Minimum
Property, Plant and Equipment
Property, plant and equipment, Useful life	3 years
Machinery and equipment \| Maximum
Property, Plant and Equipment
Property, plant and equipment, Useful life	15 years
Office equipment
Property, Plant and Equipment
Property, plant and equipment, Gross	$ 95.0	92.2
Office equipment \| Minimum
Property, Plant and Equipment
Property, plant and equipment, Useful life	3 years
Office equipment \| Maximum
Property, Plant and Equipment
Property, plant and equipment, Useful life	10 years
Construction in progress
Property, Plant and Equipment
Property, plant and equipment, Gross	$ 119.5	$ 116.1