Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	COMMON STOCK	RETAINED EARNINGS	ACCUMULATED OTHER COMPREHENSIVE LOSS
Balance at beginning of period (shares) at Apr. 30, 2022		16,570,619
Balance at beginning of period at Apr. 30, 2022	$ 772,883	$ 363,224	$ 399,434	$ 10,225
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	20,070		20,070
Other comprehensive loss, net of tax	(1,278)			(1,278)
Stock-based compensation	1,635	$ 1,635
Exercise of stock-based compensation awards, net of amounts withheld for taxes (shares)		25,908
Exercise of stock-based compensation awards, net of amounts withheld for taxes	(772)	$ (772)
Balance at end of period (shares) at Jul. 31, 2022		16,596,527
Balance at end of period at Jul. 31, 2022	792,538	$ 364,087	419,504	8,947
Balance at beginning of period (shares) at Apr. 30, 2022		16,570,619
Balance at beginning of period at Apr. 30, 2022	772,883	$ 363,224	399,434	10,225
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	48,854
Balance at end of period (shares) at Oct. 31, 2022		16,621,827
Balance at end of period at Oct. 31, 2022	829,179	$ 366,679	448,288	14,212
Balance at beginning of period (shares) at Jul. 31, 2022		16,596,527
Balance at beginning of period at Jul. 31, 2022	792,538	$ 364,087	419,504	8,947
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	28,784		28,784
Other comprehensive loss, net of tax	5,265			5,265
Stock-based compensation	1,754	$ 1,754
Exercise of stock-based compensation awards, net of amounts withheld for taxes (shares)		8,200
Exercise of stock-based compensation awards, net of amounts withheld for taxes	0	$ 0
Employee benefit plan contributions (shares)		17,100
Employee benefit plan contributions	838	$ 838
Balance at end of period (shares) at Oct. 31, 2022		16,621,827
Balance at end of period at Oct. 31, 2022	$ 829,179	$ 366,679	448,288	14,212
Balance at beginning of period (shares) at Apr. 30, 2023	16,635,295	16,635,295
Balance at beginning of period at Apr. 30, 2023	$ 873,788	$ 370,259	493,157	10,372
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	37,850		37,850
Other comprehensive loss, net of tax	914			914
Stock-based compensation	2,247	$ 2,247
Exercise of stock-based compensation awards, net of amounts withheld for taxes (shares)		55,092
Exercise of stock-based compensation awards, net of amounts withheld for taxes	(1,830)	$ (1,830)
Stock repurchases (shares)		(328,295)
Stock repurchases	(22,280)	$ (6,565)	(15,715)
Employee benefit plan contributions (shares)		50,786
Employee benefit plan contributions	3,676	$ 3,676
Balance at end of period (shares) at Jul. 31, 2023		16,412,878
Balance at end of period at Jul. 31, 2023	$ 894,365	$ 367,787	515,292	11,286
Balance at beginning of period (shares) at Apr. 30, 2023	16,635,295	16,635,295
Balance at beginning of period at Apr. 30, 2023	$ 873,788	$ 370,259	493,157	10,372
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 68,191
Balance at end of period (shares) at Oct. 31, 2023	16,026,398	16,026,398
Balance at end of period at Oct. 31, 2023	$ 895,580	$ 362,057	523,223	10,300
Balance at beginning of period (shares) at Jul. 31, 2023		16,412,878
Balance at beginning of period at Jul. 31, 2023	894,365	$ 367,787	515,292	11,286
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	30,341		30,341
Other comprehensive loss, net of tax	(986)			(986)
Stock-based compensation	2,155	$ 2,155
Exercise of stock-based compensation awards, net of amounts withheld for taxes (shares)		7,740
Exercise of stock-based compensation awards, net of amounts withheld for taxes	0	$ 0
Stock repurchases (shares)		(394,220)
Stock repurchases	$ (30,295)	$ (7,885)	(22,410)
Balance at end of period (shares) at Oct. 31, 2023	16,026,398	16,026,398
Balance at end of period at Oct. 31, 2023	$ 895,580	$ 362,057	$ 523,223	$ 10,300