Property And Equipment (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Apr. 30, 2019	Apr. 30, 2018	Apr. 30, 2017
Property, Plant and Equipment [Abstract]
Depreciation and amortization expense of property and equipment	$ 93.5	$ 103.4	$ 103.2
Outside of U.S.
Property, Plant and Equipment [Line Items]
Long-lived assets	$ 23.6	$ 24.5	$ 21.0