Condensed Consolidated Statements Of Changes In Stockholders' Equity - USD ($)	Preferred Stock [Member]	Common Stock [Member]	Capital In Excess Of Par Value [Member]	Retained Earnings [Member]	Total
Balance at Apr. 30, 2021		$ 42,560	$ 23,751,461	$ 36,755,040	$ 60,549,061
Recognition of stock-based compensation			20,035		20,035
Restricted stock awards		15	13,342		13,357
Net income				8,796,716	8,796,716
Balance at Jul. 31, 2021		42,575	23,784,838	45,551,756	69,379,169
Balance at Apr. 30, 2021		42,560	23,751,461	36,755,040	60,549,061
Net income					11,946,921
Balance at Oct. 31, 2021		43,509	24,351,902	48,701,961	73,097,372
Balance at Jul. 31, 2021		42,575	23,784,838	45,551,756	69,379,169
Recognition of stock-based compensation			122,885		122,885
Exercise of stock options		897	425,655		426,552
Restricted stock awards		37	18,524		18,561
Net income				3,150,205	3,150,205
Balance at Oct. 31, 2021		43,509	24,351,902	48,701,961	73,097,372
Balance at Apr. 30, 2022		60,379	41,654,410	46,619,208	88,333,997
Recognition of stock-based compensation			94,893		94,893
Restricted stock awards		55	49,818		49,873
Net income				1,376,675	1,376,675
Balance at Jul. 31, 2022		60,434	41,799,121	47,995,883	89,855,438
Balance at Apr. 30, 2022		60,379	41,654,410	46,619,208	88,333,997
Net income					2,248,547
Balance at Oct. 31, 2022		60,470	41,893,458	48,867,755	90,821,683
Balance at Jul. 31, 2022		60,434	41,799,121	47,995,883	89,855,438
Recognition of stock-based compensation			76,568		76,568
Restricted stock awards		36	17,769		17,805
Net income				871,872	871,872
Balance at Oct. 31, 2022		$ 60,470	$ 41,893,458	$ 48,867,755	$ 90,821,683