Condensed Consolidated Balance Sheets (Parentheticals) - USD ($) shares in Thousands, $ in Thousands	Jan. 31, 2021	Apr. 30, 2020
Statement of Financial Position [Abstract]
Allowance for doubtful accounts (in Dollars)	$ 183	$ 183
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	9,194	9,164
Common stock - authorized shares	20,000	20,000
Common stock - shares outstanding	9,193	9,121
Treasury stock, shares	1	43

Amount of allowance for credit loss on accounts receivable, classified as current.

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