Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands		Total	Class A Common Shares	Class B Common Shares	Common stock Class A Common Shares		Common stock Class B Common Shares	Additional paid-in capital	Retained earnings/deficit	Treasury stock
Beginning Balance (in shares) at Apr. 30, 2021					35,629,566		1,821,587
Beginning Balance at Apr. 30, 2021		$ 120,702			$ 3,563		$ 182	$ 159,492	$ (16,976)	$ (25,559)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Proceeds from stock options exercised (in shares)		776,129			776,129
Proceeds from stock options exercised		$ 8,578			$ 78			8,500
Stock-based compensation		3,956						3,956
Net earnings		12,805							12,805
Dividends declared ($0.44 per share)		(14,731)							(14,731)
Ending Balance (in shares) at Apr. 30, 2022					36,405,695		1,821,587
Ending Balance at Apr. 30, 2022		$ 131,310			$ 3,641		$ 182	171,948	(18,902)	(25,559)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Proceeds from stock options exercised (in shares)		501,547			501,547
Proceeds from stock options exercised		$ 5,641			$ 50			5,591
Stock-based compensation		5,183						5,183
Net earnings		10,312							10,312
Dividends declared ($0.44 per share)	[1]	(14,889)							(14,889)
Ending Balance (in shares) at Apr. 30, 2023			36,907,242	1,821,587	36,907,242		1,821,587
Ending Balance at Apr. 30, 2023		$ 137,557			$ 3,691		$ 182	182,722	(23,479)	(25,559)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Proceeds from stock options exercised (in shares)		26,253			26,253	[1]
Proceeds from stock options exercised	[1]	$ 290			$ 2			288
Purchases of common stock		(10,235)								(10,235)
Stock-based compensation		6,320						6,320
Net earnings		11,373							11,373
Dividends declared ($0.44 per share)	[1]	(14,824)							(14,824)
Ending Balance (in shares) at Apr. 30, 2024			36,933,495	1,821,587	36,933,495		1,821,587
Ending Balance at Apr. 30, 2024		$ 130,481			$ 3,693		$ 182	$ 189,330	$ (26,930)	$ (35,794)

[1] *Amounts adjusted for rounding