Income Taxes (Schedule Of Reconciliation Between Income Tax Provision And Statutory Federal Tax Rate) (Details)	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2018
Income Tax Disclosure [Abstract]
U.S. statutory tax rate	21.00%	21.00%	21.00%
State income taxes, net of federal income tax benefit	20.40%	2.30%	2.20%
Earnings taxed in foreign jurisdictions	619.40%	(2.70%)	(4.90%)
Permanent differences	(257.50%)	0.30%	0.40%
Impairment of Goodwill	(832.50%)	0.00%	0.00%
Uncertain tax positions	508.30%	(2.30%)	3.60%
U.S. tax on income from foreign affiliates	(247.40%)	0.00%	0.00%
Remeasurement of deferred tax assets and liabilities	117.60%	0.20%	(2.60%)
Changes in prior year estimates	55.50%	0.00%	0.00%
Federal income tax credits	216.30%	0.00%	0.00%
Tax impacts of stock-based compensation vesting	44.80%	0.00%	0.00%
Tax benefit due to effective date of statutory rate change	0.00%	0.00%	(15.90%)
Change in valuation allowance - domestic	37.10%	0.40%	1.10%
Change in valuation allowance - foreign	20.60%	(0.80%)	2.90%
Other	(41.20%)	(0.10%)	(1.50%)
Effective tax rate	282.40%	18.30%	6.30%