Segments - Schedule of Fee Revenue Classified by Country (Details) - USD ($) $ in Thousands	12 Months Ended
Apr. 30, 2026	Apr. 30, 2025	Apr. 30, 2024
Segment Reporting Information [Line Items]
Total fee revenue	$ 2,938,641	$ 2,761,086	$ 2,795,505
Fee revenue
Segment Reporting Information [Line Items]
Total fee revenue	2,907,469	2,730,088	2,762,671
Fee revenue \| U.S.
Segment Reporting Information [Line Items]
Total fee revenue	1,505,506	1,448,174	1,507,819
Fee revenue \| United Kingdom
Segment Reporting Information [Line Items]
Total fee revenue	386,034	327,036	262,268
Fee revenue \| Other countries
Segment Reporting Information [Line Items]
Total fee revenue	$ 1,015,929	$ 954,878	$ 992,584

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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+ Details