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Summary Of Significant Accounting Policies [Line Items]

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Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

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The aggregate amount of recurring noncash expense charged against earnings in the period to allocate the cost of assets over their estimated remaining economic lives.

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Amount charged to advertising expense for the period, which are expenses incurred with the objective of increasing revenue for a specified brand, product or product line.

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Amount of short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

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Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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Amount of difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying domestic federal statutory income tax rate to pretax income (loss) from continuing operation, attributable to excess tax benefit for share-based compensation cost.

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The aggregate amount of write-downs for impairments recognized during the period for long lived assets held for use (including those held for disposal by means other than sale).

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Amount of cash inflow (outflow) from financing activities, including discontinued operations. Financing activity cash flows include obtaining resources from owners and providing them with a return on, and a return of, their investment; borrowing money and repaying amounts borrowed, or settling the obligation; and obtaining and paying for other resources obtained from creditors on long-term credit.

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Amount of cash inflow (outflow) from operating activities, including discontinued operations. Operating activity cash flows include transactions, adjustments, and changes in value not defined as investing or financing activities.

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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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The cumulative amount of the reporting entity's undistributed earnings or deficit.

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Summary of Significant Accounting Policies (Details)	12 Months Ended
Summary of Significant Accounting Policies (Details)	Apr. 30, 2018 USD ($) plan	Apr. 30, 2017 USD ($)	Apr. 30, 2016 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Effective Income Tax Rate Reconciliation, Share-based Compensation, Excess Tax Benefit, Amount	$ 1,300,000
Advertising costs	40,100,000	$ 41,000,000	$ 38,100,000
Cash equivalents		50,100,000
Impairment of long-lived assets	0	0	0
Net increase to beginning retained earnings	$ 269,576,000	224,031,000
Number of defined benefit pension plans \| plan	2
Cash flows from operating activities	$ 86,775,000	77,080,000	74,604,000
Cash flows from financing activities	(141,027,000)	(20,821,000)	(8,909,000)
Debt issuance costs	14,304,000
Accounting Standards Update 2018-02 [Member]
Summary Of Significant Accounting Policies [Line Items]
Net increase to beginning retained earnings	8,700,000
Net decrease to accumulated other comprehensive income (loss)	$ 8,700,000
ASU 2016-09, Statutory Tax Withholding Component [Member]
Summary Of Significant Accounting Policies [Line Items]
Cash flows from operating activities		2,800,000	1,400,000
Cash flows from financing activities		(2,800,000)	(1,400,000)
Buildings And Improvements [Member] \| Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment useful lives	15 years
Buildings And Improvements [Member] \| Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment useful lives	30 years
Machinery And Equipment [Member] \| Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment useful lives	3 years
Machinery And Equipment [Member] \| Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment useful lives	12 years
Promotional Display [Member]
Summary Of Significant Accounting Policies [Line Items]
Amortization	$ 4,500,000	3,400,000	$ 3,400,000
Promotional Display [Member] \| Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment useful lives	30 months
Promotional Display [Member] \| Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment useful lives	60 months
Other Noncurrent Assets [Member] \| ASU 2015-03 [Member]
Summary Of Significant Accounting Policies [Line Items]
Debt issuance costs