Long-Term Debt - Schedule of Redemption of Notes at Applicable Redemption Prices (Detail) - 4.625% Senior Unsecured Notes due 2027	6 Months Ended
Oct. 31, 2020
2022
Debt Instrument [Line Items]
Redemption price, percentage	102.313%
2023
Debt Instrument [Line Items]
Redemption price, percentage	101.156%
2024 and thereafter
Debt Instrument [Line Items]
Redemption price, percentage	100.00%

Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph e
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

Name:	us-gaap_DebtInstrumentRedemptionPricePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration