Property and Equipment, Net - Summary of Property and Equipment (Parenthetical) (Detail) - USD ($)	12 Months Ended
Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2018
Property Plant And Equipment [Abstract]
Depreciation expense for capitalized software	$ 18,800,000	$ 14,600,000	$ 12,800,000
Net book value of capitalized software	$ 86,300,000	$ 65,800,000

Amount of expense for amortization of capitalized computer software costs.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 985
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=6501960&loc=d3e128462-111756

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 985
-SubTopic 20
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6501960&loc=d3e128487-111756

Name:	us-gaap_CapitalizedComputerSoftwareAmortization1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration