Note L - Stockholders' Equity - Schedule of Stockholders' Equity (Details) - USD ($)	3 Months Ended						9 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2021	Dec. 31, 2020
Balance	$ 80,335,001	$ 62,942,275	$ 65,339,976	$ 65,281,496	$ 65,974,090	$ 66,865,367	$ 65,339,976	$ 66,865,367
Net earnings	(2,961,833)	13,177,614	11,311,797	2,129,745	(250,005)	(858,862)	21,527,578	1,020,878
Other comprehensive loss	13,795,418	4,227,185	(13,693,337)	2,657,923
Paid in capital – restricted stock awards	128,194	126,037	121,704	104,736	110,813	110,814
Cash dividends	(138,024)	(138,110)	(137,865)	(137,867)	(143,181)	(143,229)
Net earnings	(2,961,833)	13,177,614	11,311,797	2,129,745	(250,005)	(858,862)	21,527,578	1,020,878
Issuance of restricted stock	0	0		50,000		0
Balance	91,056,681	80,335,001	62,942,275	69,352,898	65,281,496	65,974,090	91,056,681	69,352,898
Repurchase of shares	(102,075)			(733,135)	(410,221)
Common Stock [Member]
Balance	8,340,785	8,334,785	8,334,785	8,306,160	8,306,160	8,295,160	8,334,785	8,295,160
Net earnings	0			0
Other comprehensive loss	0			0
Paid in capital – restricted stock awards	0			0
Cash dividends	0			0
Net earnings	0			0
Issuance of restricted stock	4,190	6,000		28,625		11,000
Balance	8,344,975	8,340,785	8,334,785	8,334,785	8,306,160	8,306,160	8,344,975	8,334,785
Repurchase of shares	0			0
AOCI Attributable to Parent [Member]
Balance	(20,653,993)	(24,881,178)	(11,187,841)				(11,187,841)
Net earnings	0			0
Other comprehensive loss	13,795,418	4,227,185	(13,693,337)	2,657,923
Paid in capital – restricted stock awards	0			0
Cash dividends	0			0
Net earnings	0			0
Issuance of restricted stock	0			0
Balance	(6,858,575)	(20,653,993)	(24,881,178)	2,657,923			(6,858,575)	2,657,923
Repurchase of shares	0			0
Additional Paid-in Capital [Member]
Balance	30,245,203	30,125,166	30,003,462	29,776,043	29,665,230	29,565,416	30,003,462	29,565,416
Net earnings	0			0
Other comprehensive loss	0			0
Paid in capital – restricted stock awards	128,194	126,037	121,704	104,736	110,813	110,814
Cash dividends	0			0
Net earnings	0			0
Issuance of restricted stock	(4,190)			(28,625)
Balance	30,369,207	30,245,203	30,125,166	29,852,154	29,776,043	29,665,230	30,369,207	29,852,154
Repurchase of shares	0			0
Treasury Stock [Member]
Balance	(7,203,342)	(7,203,342)	(7,203,342)	(5,936,185)	(5,525,964)	(5,525,964)	(7,203,342)	(5,525,964)
Net earnings	0			0
Other comprehensive loss	0			0
Paid in capital – restricted stock awards	0			0
Cash dividends	0			0	0
Net earnings	0			0
Issuance of restricted stock	0			50,000
Balance	(7,305,417)	(7,203,342)	(7,203,342)	(6,619,320)	(5,936,185)	(5,525,964)	(7,305,417)	(6,619,320)
Repurchase of shares	(102,075)			(733,135)	(410,221)
Retained Earnings [Member]
Balance	69,606,348	56,566,844	45,392,912	33,135,478	33,528,664	34,530,755	45,392,912	34,530,755
Net earnings	(2,961,833)	13,177,614	11,311,797	2,129,745	(250,005)	(858,862)
Other comprehensive loss	0			0
Paid in capital – restricted stock awards	0			0
Cash dividends	(138,024)	(138,110)	(137,865)	(137,867)	(143,181)	(143,229)
Net earnings	(2,961,833)	13,177,614	11,311,797	2,129,745	(250,005)	(858,862)
Issuance of restricted stock	0			0
Balance	66,506,491	$ 69,606,348	$ 56,566,844	35,127,356	$ 33,135,478	$ 33,528,664	$ 66,506,491	$ 35,127,356
Repurchase of shares	$ 0			$ 0