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, 2021		16,801,101
Balance at beginning of period at Apr. 30, 2021	$ 756,238	$ 362,524	$ 448,282	$ (54,568)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	2,981		2,981
Other comprehensive loss, net of tax	(200)			(200)
Stock-based compensation	1,177	$ 1,177
Exercise of stock-based compensation awards, net of amounts withheld for taxes (shares)		20,243
Exercise of stock-based compensation awards, net of amounts withheld for taxes	(1,033)	$ (1,033)
Stock repurchases (shares)		(299,781)
Stock repurchases		$ (5,874)
Stock repurchases	(25,000)		(19,126)
Employee benefit plan contributions (shares)		39,491
Employee benefit plan contributions	2,938	$ 2,938
Balance at end of period (shares) at Jul. 31, 2021		16,561,054
Balance at end of period at Jul. 31, 2021	737,101	$ 359,732	432,137	(54,768)
Balance at beginning of period (shares) at Apr. 30, 2021		16,801,101
Balance at beginning of period at Apr. 30, 2021	756,238	$ 362,524	448,282	(54,568)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(44,246)
Balance at end of period (shares) at Jan. 31, 2022		16,570,619
Balance at end of period at Jan. 31, 2022	750,953	$ 361,898	384,910	4,145
Balance at beginning of period (shares) at Jul. 31, 2021		16,561,054
Balance at beginning of period at Jul. 31, 2021	737,101	$ 359,732	432,137	(54,768)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	2,030		2,030
Other comprehensive loss, net of tax	2,838			2,838
Stock-based compensation	1,216	$ 1,216
Exercise of stock-based compensation awards, net of amounts withheld for taxes (shares)		8,531
Exercise of stock-based compensation awards, net of amounts withheld for taxes	(46)	$ (46)
Balance at end of period (shares) at Oct. 31, 2021		16,569,585
Balance at end of period at Oct. 31, 2021	743,139	$ 360,902	434,167	(51,930)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(49,257)		(49,257)
Other comprehensive loss, net of tax	56,075			56,075
Stock-based compensation	1,006	$ 1,006
Exercise of stock-based compensation awards, net of amounts withheld for taxes (shares)		1,034
Exercise of stock-based compensation awards, net of amounts withheld for taxes	(10)	$ (10)
Balance at end of period (shares) at Jan. 31, 2022		16,570,619
Balance at end of period at Jan. 31, 2022	$ 750,953	$ 361,898	384,910	4,145
Balance at beginning of period (shares) at Apr. 30, 2022	16,570,619	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 (loss)	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	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 (loss)	$ 63,582
Balance at end of period (shares) at Jan. 31, 2023	16,621,827	16,621,827
Balance at end of period at Jan. 31, 2023	$ 843,140	$ 368,539	463,016	11,585
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 (loss)	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
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	14,728		14,728
Other comprehensive loss, net of tax	(2,627)			(2,627)
Stock-based compensation	$ 1,860	$ 1,860
Balance at end of period (shares) at Jan. 31, 2023	16,621,827	16,621,827
Balance at end of period at Jan. 31, 2023	$ 843,140	$ 368,539	$ 463,016	$ 11,585