Comprehensive Income - Changes in Each Component of Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jan. 31, 2024	Jan. 31, 2023	Jan. 31, 2024	Jan. 31, 2023
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance			$ 1,648,071
Unrealized (losses) gains arising during the period	$ 12,914	$ 39,803	(10,250)	$ (4,782)
Reclassification of realized net losses to net income	29	60	84	165
Ending balance	1,703,623		1,703,623
Tax effect on unrealized gains (losses), securities, tax expense (benefit)	100	100	100
Tax effect on reclassification of realized net losses, tax benefit			100	100
Foreign Currency Translation
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(120,196)	(136,991)	(96,860)	(92,717)
Unrealized (losses) gains arising during the period	12,742	39,482	(10,594)	(4,792)
Reclassification of realized net losses to net income	0	0	0	0
Ending balance	(107,454)	(97,509)	(107,454)	(97,509)
Deferred Compensation and Pension Plan
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	4,436	1,066	4,381	961
Unrealized (losses) gains arising during the period	0	0	0	0
Reclassification of realized net losses to net income	29	60	84	165
Ending balance	4,465	1,126	4,465	1,126
Unrealized (Losses) Gains on Marketable Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(113)	(740)	(285)	(429)
Unrealized (losses) gains arising during the period	172	321	344	10
Reclassification of realized net losses to net income	0	0	0	0
Ending balance	59	(419)	59	(419)
Accumulated Other Comprehensive Loss, Net
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(115,873)	(136,665)	(92,764)	(92,185)
Ending balance	$ (102,930)	$ (96,802)	$ (102,930)	$ (96,802)