Property, Plant and Equipment (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Sep. 30, 2018	Mar. 31, 2018
Property, Plant and Equipment [Line Items]
Gross property, plant and equipment	$ 1,286.4	$ 1,302.2
Less: accumulated depreciation	(800.7)	(797.9)
Net property, plant and equipment	485.7	504.3
Land [Member]
Property, Plant and Equipment [Line Items]
Gross property, plant and equipment	21.3	22.6
Buildings and Improvements [Member]
Property, Plant and Equipment [Line Items]
Gross property, plant and equipment	$ 289.3	$ 295.6
Buildings and Improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, depreciable lives	10 years	10 years
Buildings and Improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, depreciable lives	40 years	40 years
Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Gross property, plant and equipment	$ 829.0	$ 840.8
Machinery and Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, depreciable lives	3 years	3 years
Machinery and Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, depreciable lives	12 years	12 years
Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Gross property, plant and equipment	$ 90.9	$ 93.0
Office Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, depreciable lives	3 years	3 years
Office Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, depreciable lives	10 years	10 years
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Gross property, plant and equipment	$ 55.9	$ 50.2