Other Financial Statement Details - Property, Plant and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	$ 2,966.1	$ 2,945.7
Less accumulated depreciation and amortization	2,090.0	1,949.0
Total property, plant and equipment, net	876.1	996.7
Depreciation expense	168.9	180.6	$ 123.7
Land
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	83.4	83.4
Building and building improvements
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	659.5	647.6
Machinery and equipment
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	2,123.1	2,095.5
Projects in process
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, gross	$ 100.1	$ 119.2