Financial Derivatives and Hedging - Schedule of Fair Values of Derivative Instruments in Condensed Consolidated Balance Sheets (Details) - Designated as Hedging Instrument - Interest Rate Swap - USD ($) $ in Thousands	Apr. 30, 2021	Apr. 30, 2020
Derivatives, Fair Value [Line Items]
Interest rate swap contracts, assets	$ 9,500	$ 0
Interest rate swap contracts, assets, liabilities	600	17,100
Other current assets
Derivatives, Fair Value [Line Items]
Interest rate swap contracts, assets	0	0
Other non-current assets
Derivatives, Fair Value [Line Items]
Interest rate swap contracts, assets	9,500	0
Other current liabilities
Derivatives, Fair Value [Line Items]
Interest rate swap contracts, assets, liabilities	100	600
Other non-current liabilities
Derivatives, Fair Value [Line Items]
Interest rate swap contracts, assets, liabilities	$ 500	$ 16,500