STATEMENTS OF SHAREHOLDERS' EQUITY (Unaudited) - USD ($)	Common Stock	Additional Paid-in Capital	AOCI Including Portion Attributable to Noncontrolling Interest	Retained Earnings	Total
Equity Balance, Starting at Mar. 31, 2023	$ 48,308	$ 19,295,442	$ (1,213,858)	$ 48,949,610	$ 67,079,502
Shares Outstanding, Starting at Mar. 31, 2023	4,830,826
Unrealized loss from marketable securities, net of tax			(234,701)		(234,701)
Net income				4,403,730	4,403,730
Total comprehensive income					4,169,029
Shares Granted, Value, Share-Based Payment Arrangement, after Forfeiture		10,536			10,536
Cash dividends ($1.00 per share of common stock)				(4,830,826)	(4,830,826)
Stock Issued During Period, Value, Stock Options Exercised	$ 26	117,501			117,527
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period	2,575
Shares Outstanding, Ending at Jun. 30, 2023	4,833,401
Equity Balance, Ending at Jun. 30, 2023	$ 48,334	19,423,479	(1,448,559)	48,522,514	66,545,768
Equity Balance, Starting at Mar. 31, 2023	$ 48,308	19,295,442	(1,213,858)	48,949,610	67,079,502
Shares Outstanding, Starting at Mar. 31, 2023	4,830,826
Unrealized loss from marketable securities, net of tax					(288,289)
Net income					9,127,296
Total comprehensive income					$ 8,839,007
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period					1,000
Shares Outstanding, Ending at Sep. 30, 2023	4,833,401
Equity Balance, Ending at Sep. 30, 2023	$ 48,334	19,529,791	(1,502,147)	48,412,679	$ 66,488,657
Equity Balance, Starting at Jun. 30, 2023	$ 48,334	19,423,479	(1,448,559)	48,522,514	66,545,768
Shares Outstanding, Starting at Jun. 30, 2023	4,833,401
Unrealized loss from marketable securities, net of tax			(53,588)		(53,588)
Net income				4,723,566	4,723,566
Total comprehensive income					4,669,978
Shares Granted, Value, Share-Based Payment Arrangement, after Forfeiture		106,312			106,312
Cash dividends ($1.00 per share of common stock)				(4,833,401)	$ (4,833,401)
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period					0
Shares Outstanding, Ending at Sep. 30, 2023	4,833,401
Equity Balance, Ending at Sep. 30, 2023	$ 48,334	19,529,791	(1,502,147)	48,412,679	$ 66,488,657
Equity Balance, Starting at Mar. 31, 2024	$ 48,337	19,554,812	(777,637)	46,743,005	65,568,517
Shares Outstanding, Starting at Mar. 31, 2024	4,833,676
Unrealized loss from marketable securities, net of tax			28,710		28,710
Net income				4,097,587	4,097,587
Total comprehensive income					4,126,297
Shares Granted, Value, Share-Based Payment Arrangement, after Forfeiture		18,442			18,442
Cash dividends ($1.00 per share of common stock)				(4,833,676)	(4,833,676)
Shares Outstanding, Ending at Jun. 30, 2024	4,833,676
Equity Balance, Ending at Jun. 30, 2024	$ 48,337	19,573,254	(748,927)	46,006,916	64,879,580
Equity Balance, Starting at Mar. 31, 2024	$ 48,337	19,554,812	(777,637)	46,743,005	65,568,517
Shares Outstanding, Starting at Mar. 31, 2024	4,833,676
Unrealized loss from marketable securities, net of tax					709,127
Net income					8,123,732
Total comprehensive income					$ 8,832,859
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period					0
Shares Outstanding, Ending at Sep. 30, 2024	4,834,020
Equity Balance, Ending at Sep. 30, 2024	$ 48,340	19,678,425	(68,510)	45,199,385	$ 64,857,640
Equity Balance, Starting at Jun. 30, 2024	$ 48,337	19,573,254	(748,927)	46,006,916	64,879,580
Shares Outstanding, Starting at Jun. 30, 2024	4,833,676
Unrealized loss from marketable securities, net of tax			680,417		680,417
Net income				4,026,145	4,026,145
Total comprehensive income					4,706,562
Shares Granted, Value, Share-Based Payment Arrangement, after Forfeiture		105,203			105,203
Cash dividends ($1.00 per share of common stock)				(4,833,676)	(4,833,676)
Stock Issued During Period, Value, Stock Options Exercised	$ 3	(32)			$ (29)
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period	344				1,000
Shares Outstanding, Ending at Sep. 30, 2024	4,834,020
Equity Balance, Ending at Sep. 30, 2024	$ 48,340	$ 19,678,425	$ (68,510)	$ 45,199,385	$ 64,857,640