Other Financial Statement Details - Property, Plant and Equipment (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Mar. 31, 2021
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	$ 3,247.3		$ 3,247.3		$ 3,096.7
Less: accumulated depreciation and amortization	2,323.6		2,323.6		2,242.0
Total property, plant and equipment, net	923.7		923.7		854.7
Depreciation expense	43.7	$ 39.0	84.9	$ 80.1
Land
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	82.5		82.5		83.2
Building and building improvements
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	659.4		659.4		659.7
Machinery and equipment
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	2,404.7		2,404.7		2,251.1
Projects in process
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	$ 100.7		$ 100.7		$ 102.7