Note L - Stockholders' Equity - Schedule of Stockholders' Equity (Details) (Parentheticals) - $ / shares	3 Months Ended				6 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Sep. 30, 2019	Jun. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Cash dividends, per share (in dollars per share)	$ 0.02		$ 0.02		$ 0.04	$ 0.06
Retained Earnings [Member]
Cash dividends, per share (in dollars per share)		$ 0.02		$ 0.04