Fair Value Measurements - Summary of Fair Values of Company's Marketable Securities By Type (Detail) - USD ($) $ in Thousands	Apr. 30, 2025	Apr. 30, 2024
Marketable Securities [Line Items]
Amortized Cost	$ 87,744	$ 178,327
Unrealized Gains	1,258	683
Unrealized Losses		(398)
Fair Value	89,002	178,612
Corporate Debt Securities [Member]
Marketable Securities [Line Items]
Amortized Cost	74,150	130,099
Unrealized Gains	1,093	600
Unrealized Losses		(276)
Fair Value	75,243	130,423
Obligations of U.S. Government and Its Agencies [Member]
Marketable Securities [Line Items]
Amortized Cost	13,594	48,228
Unrealized Gains	165	83
Unrealized Losses		(122)
Fair Value	$ 13,759	$ 48,189