Condensed Consolidated Statements of Equity (Unaudited) - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Treasury Stock, Common [Member]	Noncontrolling Interest [Member]	Total
Balance (in shares) at Apr. 30, 2022	13,642,185
Balance at Apr. 30, 2022	$ 136	$ 103,113	$ 665,410	$ (292,225)	$ 100	$ 476,534
Issuance of common stock (in shares)	30,484
Issuance of common stock	$ 1	84	0	0	0	85
Stock options exercised (in shares)	23,000
Stock options exercised	$ 0	1,216	0	0	0	1,216
Purchase of treasury shares	0	0	0	(5,196)	0	(5,196)
Stock based compensation	0	1,978	0	0	0	1,978
Dividends on subsidiary preferred stock	0	0	(10)	0	0	(10)
Net income	$ 0	0	13,697	0	0	13,697
Balance (in shares) at Jul. 31, 2022	13,695,669
Balance at Jul. 31, 2022	$ 137	106,391	679,097	(297,421)	100	488,304
Balance (in shares) at Apr. 30, 2023	13,701,468
Balance at Apr. 30, 2023	$ 137	109,929	685,802	(297,421)	100	498,547
Issuance of common stock (in shares)	2,921
Issuance of common stock	$ 0	78	0	0	0	78
Stock options exercised (in shares)	6,493
Stock options exercised	$ 0	(455)	0	0	0	(455)
Purchase of treasury shares	0	0	0	(68)	0	(68)
Stock based compensation	0	2,451	0	0	0	2,451
Dividends on subsidiary preferred stock	0	0	(10)	0	0	(10)
Net income	$ 0	0	4,186	0	0	4,186
Balance (in shares) at Jul. 31, 2023	13,710,882
Balance at Jul. 31, 2023	$ 137	$ 112,003	$ 689,978	$ (297,489)	$ 100	$ 504,729