Fee Revenue - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Apr. 30, 2025	Apr. 30, 2024	Apr. 30, 2023
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Contract liabilities, revenue recognized	$ 184.9	$ 195.2	$ 181.7
Revenue recognized, remaining performance obligation	1,156.5
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	$ 565.5
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	$ 363.2
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	$ 169.2
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2028-05-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue recognized, remaining performance obligation	$ 58.6
Revenue, remaining performance obligation, expected timing of satisfaction, period