Fair Value Measurements - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2021	Apr. 30, 2020	Apr. 30, 2019	Feb. 28, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swap gains (losses)		$ 0	$ 0	$ (6,395)
ROU asset impairment	$ 1,900	1,000
Impairment of goodwill	$ 63,100	0	63,074	$ 0
Interest rate swap agreements
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swap gains (losses)		(8,800)	$ (2,000)
Expected amount of pre-tax net losses will be reclassified from accumulated other comprehensive income (loss) into earnings during the next twelve months		11,800
Interest rate swap agreements | Other Accrued Expenses And Current Liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		11,800
Interest rate swap agreements | Other Liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		$ 9,200
Term Loan Facility | Interest rate swap agreements
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional amount					$ 500,000
Term Loan Facility | Interest rate swap agreements | LIBOR
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Capped interest rate (as a percent)					2.46%