Fee Revenue - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Apr. 30, 2024	Apr. 30, 2023	Apr. 30, 2022
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Contract liabilities, revenue recognized	$ 195.2	$ 181.7	$ 131.3
Revenue recognized, remaining performance obligation	1,013.8
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2024-05-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue recognized, remaining performance obligation	$ 545.8
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2025-05-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue recognized, remaining performance obligation	$ 288.3
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2026-05-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue recognized, remaining performance obligation	$ 131.6
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2027-05-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue recognized, remaining performance obligation	$ 48.1
Revenue, remaining performance obligation, expected timing of satisfaction, period