GOODWILL AND INTANGIBLE ASSETS (Schedule of Goodwill) (Details) - USD ($) $ in Thousands	9 Months Ended
	Jan. 31, 2021	Jan. 31, 2020
Goodwill [Roll Forward]
Goodwill before impairment losses, beginning balance	$ 850,435	$ 552,234
Accumulated impairment losses, beginning balance	(138,297)	(32,297)
Goodwill, beginning balance	712,138	519,937
Acquisitions	6,924	23,421
Disposals and foreign currency changes, net	26,554	(5,088)
Impairments	0	0
Goodwill before impairment losses, ending balance	883,913	871,127
Accumulated impairment losses, ending balance	(138,297)	(32,297)
Goodwill, ending balance	$ 745,616	838,830
Wave
Goodwill [Roll Forward]
Acquisitions		$ 300,560