Note H - Weighted Average Shares Outstanding - Weighted Average Shares of Common Stock Outstanding (Details) - shares	3 Months Ended		6 Months Ended
	Oct. 31, 2016	Oct. 31, 2015	Oct. 31, 2016	Oct. 31, 2015
Employee Stock Option [Member]
Antidilutive securities not included:
Antidilutive securities (in shares)	343,250	251,000	376,875	254,500
Restricted Stock [Member]
Antidilutive securities not included:
Antidilutive securities (in shares)	10,000	9,500	9,500	4,750
Weighted average shares outstanding-basic (in shares)	7,833,061	8,471,918	7,890,993	8,492,679
Dilutive options and restricted stock (in shares)	303,900	0	270,026	360,942
Weighted average shares outstanding-diluted (in shares)	8,136,961	8,471,918	8,161,019	8,853,621