Balance Sheet Components - Property, Plant and Equipment (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Feb. 01, 2020	Jan. 26, 2019	Feb. 01, 2020	Jan. 26, 2019	Apr. 27, 2019
Property, Plant and Equipment, Net [Abstract]
Total Property, Plant and Equipment, Gross	$ 497.9		$ 497.9		$ 475.6
Less: Accumulated Depreciation	298.9		298.9		283.7
Property, Plant and Equipment, Net	199.0		199.0		191.9
Depreciation	7.5	$ 6.7	21.7	$ 19.5
Capital expenditures recorded in accounts payable			2.0		6.4
Land
Property, Plant and Equipment, Net [Abstract]
Total Property, Plant and Equipment, Gross	3.4		3.4		3.7
Buildings and Building Improvements
Property, Plant and Equipment, Net [Abstract]
Total Property, Plant and Equipment, Gross	85.9		$ 85.9		81.2
Buildings and Building Improvements | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life			5 years
Buildings and Building Improvements | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life			40 years
Machinery and Equipment
Property, Plant and Equipment, Net [Abstract]
Total Property, Plant and Equipment, Gross	$ 408.6		$ 408.6		$ 390.7
Machinery and Equipment | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life			3 years
Machinery and Equipment | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life			15 years