Description of Business and Summary of Significant Accounting Policies - Property, Plant and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
Apr. 27, 2019	Apr. 28, 2018	Apr. 29, 2017
Property, Plant and Equipment, Net [Abstract]
Land	$ 3.7	$ 0.8
Buildings and Building Improvements	81.2	69.2
Machinery and Equipment	390.7	364.7
Total Property, Plant and Equipment, Gross	475.6	434.7
Less: Accumulated Depreciation	283.7	272.5
Property, Plant and Equipment, Net	191.9	162.2	$ 90.6
Depreciation	27.2	22.5	$ 22.0
Capital expenditures incurred but not yet paid	$ 6.4	$ 9.0
Buildings and improvements \| Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives of property, plant and equipment	5 years
Buildings and improvements \| Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives of property, plant and equipment	40 years
Machinery and equipment \| Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives of property, plant and equipment	3 years
Machinery and equipment \| Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives of property, plant and equipment	15 years

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Amount before accumulated depreciation of building structures held for productive use including addition, improvement, or renovation to the structure, including, but not limited to, interior masonry, interior flooring, electrical, and plumbing.

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Future cash outflow to pay for purchases of fixed assets that have occurred.

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The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

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Amount before accumulated depletion of real estate held for productive use, excluding land held for sale.

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Amount before accumulated depreciation of tangible personal property used to produce goods and services, including, but is not limited to, tools, dies and molds, computer and office equipment.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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