Note L - Stockholders' Equity - Schedule of Stockholders' Equity (Details) - USD ($)	3 Months Ended						6 Months Ended	9 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Balance			$ 66,865,367					$ 66,865,367
Net earnings (loss)	$ 2,129,745			$ (881,003)				1,020,878	$ (2,230,368)
Repurchase of shares							$ (1,143,356)
Other comprehensive income	2,657,923							2,657,923
Balance	69,352,898						69,352,898	69,352,898
Common Stock [Member]
Balance	8,306,160	$ 8,306,160	8,295,160	8,225,160	$ 8,225,160	$ 8,205,160		8,295,160	8,205,160
Net earnings (loss)
Issuance of restricted stock	28,625		11,000			20,000
Paid in capital – restricted stock awards
Cash dividends
Repurchase of shares
Other comprehensive income
Balance	8,334,785	8,306,160	8,306,160	8,225,160	8,225,160	8,225,160	8,334,785	8,334,785	8,225,160
AOCI Attributable to Parent [Member]
Balance
Net earnings (loss)
Issuance of restricted stock
Paid in capital – restricted stock awards
Cash dividends
Repurchase of shares
Other comprehensive income	2,657,923
Balance	2,657,923						2,657,923	2,657,923
Additional Paid-in Capital [Member]
Balance	29,776,043	29,665,230	29,565,416	29,468,944	29,385,708	29,322,472		29,565,416	29,322,472
Net earnings (loss)
Issuance of restricted stock
Paid in capital – restricted stock awards	76,111	110,813	99,814	83,236	83,236	63,236
Cash dividends
Repurchase of shares
Other comprehensive income
Balance	29,852,154	29,776,043	29,665,230	29,552,180	29,468,944	29,385,708	29,852,154	29,852,154	29,552,180
Treasury Stock [Member]
Balance	(5,936,185)	(5,525,964)	(5,525,964)	(5,525,964)	(5,525,964)	(5,525,964)		(5,525,964)	(5,525,964)
Net earnings (loss)
Issuance of restricted stock	50,000
Paid in capital – restricted stock awards
Cash dividends
Repurchase of shares	(733,135)	(410,221)
Other comprehensive income
Balance	(6,619,320)	(5,936,185)	(5,525,964)	(5,525,964)	(5,525,964)	(5,525,964)	(6,619,320)	(6,619,320)	(5,525,964)
Retained Earnings [Member]
Balance	33,135,478	33,528,664	34,530,755	38,710,576	40,394,703	40,479,909		34,530,755	40,479,909
Net earnings (loss)	2,129,745	(250,005)	(858,862)	(881,003)	(1,544,137)	194,772
Issuance of restricted stock
Paid in capital – restricted stock awards
Cash dividends	(137,867)	(143,181)	(143,229)	(139,993)	(139,990)	(279,978)
Repurchase of shares
Other comprehensive income
Balance	$ 35,127,356	$ 33,135,478	$ 33,528,664	$ 37,689,580	$ 38,710,576	$ 40,394,703	$ 35,127,356	$ 35,127,356	$ 37,689,580