Income Taxes (Schedule Of Reconciliation Between Income Tax Provision And Statutory Federal Tax Rate) (Details)	12 Months Ended
	Apr. 30, 2019	Apr. 30, 2018	Apr. 30, 2017
Income Tax Disclosure [Abstract]
U.S. statutory tax rate	21.00%	21.00%	35.00%
State income taxes, net of federal income tax benefit	2.30%	2.20%	1.60%
Earnings taxed in foreign jurisdictions	(2.70%)	(4.90%)	(4.60%)
Permanent differences	0.30%	0.40%	(0.40%)
Uncertain tax positions	(2.30%)	3.60%	4.30%
Remeasurement of deferred tax assets and liabilities	0.20%	(2.60%)	(0.00%)
Tax benefit due to effective date of statutory rate change	(0.00%)	(15.90%)	(0.00%)
One-time transition tax	0.00%	2.90%	0.00%
Tax deductible write-down of foreign investment	(0.00%)	(2.40%)	(0.00%)
Change in valuation allowance - domestic	0.40%	1.10%	(0.10%)
Change in valuation allowance - foreign	(0.80%)	2.90%	0.30%
Other	(0.10%)	(2.00%)	(3.00%)
Effective tax rate	18.30%	6.30%	33.10%