Note H - Weighted Average Shares Outstanding - Weighted Average Shares of Common Stock Outstanding (Details) - shares	3 Months Ended		9 Months Ended
	Jan. 31, 2017	Jan. 31, 2016	Jan. 31, 2017	Jan. 31, 2016
Weighted average shares outstanding-basic (in shares)	7,893,737	8,367,728	7,891,908	8,451,029
Dilutive options and restricted stock (in shares)	282,017	248,029	274,023	323,305
Weighted average shares outstanding-diluted (in shares)	8,175,754	8,615,757	8,165,931	8,774,334
Employee Stock Option [Member]
Antidilutive securities not included:
Antidilutive securities (in shares)	327,750	373,000	360,500	294,000
Restricted Stock [Member]
Antidilutive securities not included:
Antidilutive securities (in shares)		9,500	6,333	6,333