Note L - Stockholders' Equity - Schedule of Stockholders' Equity (Details) - USD ($)	3 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Balance	$ 66,865,367
Net earnings	(858,862)	$ 194,772
Balance	65,974,090
Common Stock [Member]
Balance	8,295,160	8,205,160
Net earnings
Issuance of restricted stock	11,000	20,000
Paid in capital – restricted stock awards
Cash dividends
Balance	8,306,160	8,225,160
Additional Paid-in Capital [Member]
Balance	29,565,416	29,322,472
Net earnings
Issuance of restricted stock
Paid in capital – restricted stock awards	99,814	63,236
Cash dividends
Balance	29,665,230	29,385,708
Treasury Stock [Member]
Balance	(5,525,964)	(5,525,964)
Net earnings
Issuance of restricted stock
Paid in capital – restricted stock awards
Cash dividends
Balance	(5,525,964)	(5,525,964)
Retained Earnings [Member]
Balance	34,530,755	40,479,909
Net earnings	(858,862)	194,772
Issuance of restricted stock
Paid in capital – restricted stock awards
Cash dividends	(143,229)	(279,978)
Balance	$ 33,528,664	$ 40,394,703