Condensed Consolidated Balance Sheets (Parentheticals) - USD ($) shares in Thousands, $ in Thousands	Oct. 31, 2017	Apr. 30, 2017
Allowance for doubtful accounts (in Dollars)	$ 187	$ 187
Preferred stock, par value (in Dollars per share)	$ 1.00	$ 1.00
Preferred stock - shares authorized	600	600
Preferred stock - shares issued	0	0
Common stock, par value (in Dollars per share)	$ 1.00	$ 1.00
Common stock shares issued	9,164	9,164
Common stock - authorized shares	20,000	20,000
Common stock - shares outstanding	8,843	8,817
Treasury stock, shares	321	347