Segments - Long Lived Assets, Excluding Financial Instruments and Tax Assets, Classified by Controlling Countries over Ten Percent (Detail) - USD ($) $ in Thousands	Apr. 30, 2023	Apr. 30, 2022	Apr. 30, 2021
Segment Reporting Information [Line Items]
Long-lived assets	$ 304,566	$ 305,906	$ 305,899
U.S.
Segment Reporting Information [Line Items]
Long-lived assets	186,220	185,228	182,218
United Kingdom
Segment Reporting Information [Line Items]
Long-lived assets	22,893	26,711	34,081
Other countries
Segment Reporting Information [Line Items]
Long-lived assets	$ 95,453	$ 93,967	$ 89,600