Segment Information, Reconciliation of Consolidated U.S. GAAP Operating Income (Loss) to Non-GAAP Adjusted Contribution to Profit (Details) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
		Apr. 30, 2021	Jan. 31, 2021	Oct. 31, 2020	Jul. 31, 2020	Apr. 30, 2020	Jan. 31, 2020	Oct. 31, 2019	Jul. 31, 2019	Apr. 30, 2021	Apr. 30, 2020	Apr. 30, 2019
Reconciliation of Consolidated US GAAP Operating Income (Loss) to Non-GAAP Adjusted Contribution to Profit [Abstract]
US GAAP Operating Income (Loss)		$ 51,200	$ 34,400	$ 69,900	$ 30,000	$ (170,700)	$ 48,500	$ 63,400	$ 4,500	$ 185,511	$ (54,287)	$ 223,989
Adjustments [Abstract]
Restructuring and related charges (credit)	[1]									33,310	32,607	3,118
Impairment of goodwill	[1]									0	110,000	0
Non-GAAP Adjusted Contribution to Profit										218,821	180,668	227,107
Developed Technology [Member]
Adjustments [Abstract]
Impairment of intangible assets	[1]									0	2,841	0
Blackwell Trade Name [Member]
Adjustments [Abstract]
Impairment of intangible assets	[1]									$ 0	$ 89,507	$ 0

[1] See Note 7, “Restructuring and Related Charges” and Note 11, “Goodwill and Intangible Assets” for these charges by segment.