Note H - Weighted Average Shares Outstanding - Weighted Average Shares of Common Stock Outstanding (Details) - shares	3 Months Ended		6 Months Ended
	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2017	Oct. 31, 2016
Weighted average shares outstanding-basic (in shares)	7,354,499	7,833,061	7,451,673	7,890,993
Dilutive options and restricted stock (in shares)	200,527	303,900	209,995	270,026
Weighted average shares outstanding-diluted (in shares)	7,555,026	8,136,961	7,661,668	8,161,019
Employee Stock Option [Member]
Antidilutive securities not included:
Antidilutive securities (in shares)	314,750	343,250	326,250	376,875
Restricted Stock [Member]
Antidilutive securities not included:
Antidilutive securities (in shares)		10,000	17,000	9,500