Fee Revenue - Schedule of Disaggregation of Fee Revenue by Industry (Detail) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2024	Apr. 30, 2023	Apr. 30, 2022
Disaggregation Of Revenue [Line Items]
Fee revenue	$ 2,795,505	$ 2,863,836	$ 2,643,455
Industrial
Disaggregation Of Revenue [Line Items]
Fee revenue	$ 813,919	$ 805,241	$ 688,902
Fee revenue, percentage	29.50%	28.40%	26.20%
Financial Services
Disaggregation Of Revenue [Line Items]
Fee revenue	$ 491,761	$ 494,299	$ 475,326
Fee revenue, percentage	17.80%	17.40%	18.10%
Life Sciences/Healthcare
Disaggregation Of Revenue [Line Items]
Fee revenue	$ 485,321	$ 522,372	$ 501,463
Fee revenue, percentage	17.60%	18.40%	19.10%
Technology
Disaggregation Of Revenue [Line Items]
Fee revenue	$ 404,569	$ 483,787	$ 456,498
Fee revenue, percentage	14.60%	17.10%	17.40%
Consumer Goods
Disaggregation Of Revenue [Line Items]
Fee revenue	$ 382,175	$ 386,409	$ 372,720
Fee revenue, percentage	13.80%	13.60%	14.20%
Education/Non–Profit/General
Disaggregation Of Revenue [Line Items]
Fee revenue	$ 184,926	$ 143,300	$ 131,809
Fee revenue, percentage	6.70%	5.10%	5.00%
Fee Revenue
Disaggregation Of Revenue [Line Items]
Fee revenue	$ 2,762,671	$ 2,835,408	$ 2,626,718
Fee revenue, percentage	100.00%	100.00%	100.00%