Income Taxes (Schedule of Rate Reconciliation) (Details)	9 Months Ended
	Jan. 31, 2019	Jan. 31, 2018
Income Tax Disclosure [Abstract]
U.S. statutory tax rate	21.00%	21.00%
State income taxes, net of federal income tax benefit	2.10%	2.20%
Earnings taxed in foreign jurisdictions	(3.20%)	(2.30%)
Permanent differences	0.30%	0.30%
Uncertain tax positions	4.30%	6.00%
Remeasurement of deferred tax assets and liabilities	(0.10%)	2.40%
Tax benefit due to effective date of statutory rate change	0.00%	(16.40%)
One-time transition tax	0.00%	(2.40%)
Other	1.00%	(3.10%)
Effective tax rate	25.40%	7.70%