Consolidated Statements of Changes in Equity - USD ($)	Preferred Stock [Member] Series 2003 Preferred Stock [Member]	Preferred Stock [Member]	Common Stock [Member] Common Stock Retired [Member]	Common Stock [Member]	Treasury Stock, Common [Member] Common Stock Retired [Member]	Treasury Stock, Common [Member]	Additional Paid-in Capital [Member] Series 2003 Preferred Stock [Member]	Additional Paid-in Capital [Member] Common Stock Retired [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member] Series 2003 Preferred Stock [Member]	Retained Earnings [Member] Common Stock Retired [Member]	Retained Earnings [Member]	Series 2003 Preferred Stock [Member]	Common Stock Retired [Member]	Total
Balances (in shares) at May. 31, 2023		50,000		28,279,701
Balances at May. 31, 2023		$ 5		$ 2,828		$ 0			$ 53,533,272			$ (33,995,621)			$ 19,540,484
Balances (in shares) at May. 31, 2023						0
Preferred dividends		0		0		$ 0			0			(587,226)			(587,226)
Net income		$ 0		$ 0		0			0			5,027,491			5,027,491
Balances (in shares) at May. 31, 2024		50,000		28,279,701
Balances at May. 31, 2024		$ 5		$ 2,828		$ 0			53,533,272			(29,555,356)			23,980,749
Balances (in shares) at May. 31, 2024						0
Preferred dividends		0		0		$ 0			0			(428,713)			(428,713)
Net income		$ 0		$ 0		$ 0			0			2,351,010			2,351,010
Retirement of stock (in shares)	(50,000)		(400,000)
Retirement of stock	$ (5)		$ (40)				$ (4,999,995)	$ (419,960)		$ 0	$ 0		$ (5,000,000)	$ (420,000)
Repurchase of common stock (in shares)					0	519,124
Repurchase of common stock					$ 0	$ (606,737)			0			0			(606,737)
Balances (in shares) at May. 31, 2025		0		27,879,701
Balances at May. 31, 2025		$ 0		$ 2,788		$ (606,737)			$ 48,113,317			$ (27,633,059)			$ 19,876,309
Balances (in shares) at May. 31, 2025						519,124									519,124