Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]
Beginning Balance, Shares at Apr. 30, 2021		16,801,101
Beginning Balance at Apr. 30, 2021	$ 756,238	$ 362,524	$ 448,282	$ (54,568)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(29,722)		(29,722)
Other comprehensive income (loss), net of tax	64,793			64,793
Stock-based compensation	4,708	$ 4,708
Exercise of stock-based compensation awards, net of amounts withheld for taxes, shares		29,808
Exercise of stock-based compensation awards, net of amounts withheld for taxes	(1,072)	$ (1,072)
Stock repurchases, shares		(299,781)
Stock repurchases	(25,000)	$ (5,874)	(19,126)
Employee benefit plan contributions, shares		39,491
Employee benefit plan contributions	2,938	$ 2,938
Ending Balance, Shares at Apr. 30, 2022		16,570,619
Ending Balance at Apr. 30, 2022	772,883	$ 363,224	399,434	10,225
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	93,723		93,723
Other comprehensive income (loss), net of tax	147			147
Stock-based compensation	7,396	$ 7,396
Exercise of stock-based compensation awards, net of amounts withheld for taxes, shares		47,576
Exercise of stock-based compensation awards, net of amounts withheld for taxes	(1,199)	$ (1,199)
Employee benefit plan contributions, shares		17,100
Employee benefit plan contributions	$ 838	$ 838
Ending Balance, Shares at Apr. 30, 2023	16,635,295	16,635,295
Ending Balance at Apr. 30, 2023	$ 873,788	$ 370,259	493,157	10,372
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	116,216		116,216
Other comprehensive income (loss), net of tax	(3,054)			(3,054)
Stock-based compensation	$ 10,682	$ 10,682
Exercise of stock-based compensation awards, net of amounts withheld for taxes, shares	0	76,097
Exercise of stock-based compensation awards, net of amounts withheld for taxes	$ (2,492)	$ (2,492)
Stock repurchases, shares		(1,108,715)
Stock repurchases	(88,440)	$ (22,341)	(66,099)
Employee benefit plan contributions, shares		50,786
Employee benefit plan contributions	$ 3,676	$ 3,676
Ending Balance, Shares at Apr. 30, 2024	15,653,463	15,653,463
Ending Balance at Apr. 30, 2024	$ 910,376	$ 359,784	$ 543,274	$ 7,318