Income Taxes (Effective Tax Rate Reconciliation) (Details)	12 Months Ended
Apr. 30, 2021	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2017
Reconciles our effective tax rate to the federal statutory tax rate in the United States
U.S. federal statutory rate	21.00%	21.00%	21.00%	35.00%
State taxes, net of U.S. federal tax benefit	2.40%	1.70%	2.10%
Income taxed at other than U.S. federal statutory rate	0.30%	0.00%	(0.10%)
Tax benefit from foreign-derived sales	(1.70%)	(2.00%)	(1.70%)
Adjustments related to prior years	(0.20%)	(1.10%)	(1.20%)
Excess tax benefits from stock-based awards	(1.00%)	(2.00%)	(0.70%)
Impact of Tax Act	0.00%	0.00%	(0.40%)
Intercompany transfer of assets	(4.00%)	0.00%	0.00%
Other, net	(0.30%)	0.40%	0.80%
Effective rate	16.50%	18.00%	19.80%

Effective Income Tax Rate Reconciliation, Tax Cuts and Jobs Act, Percent

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Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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-Publisher FASB
-Name Accounting Standards Codification
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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to other deductions.

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Percentage 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 operations, attributable to disposition of asset. Includes, but is not limited to, intra-entity transfer of asset other than inventory.

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Percentage 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 expense for award under share-based payment arrangement. Excludes expense determined to be nondeductible upon grant or after for award under share-based payment arrangement.

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