Condensed Consolidated Balance Sheets (Parentheticals) (USD $) In Thousands, except Per Share data, unless otherwise specified	Jan. 31, 2015	Apr. 30, 2014
Allowance for doubtful accounts	$ 216	$ 234
Preferred stock- par value	$ 1.00	$ 1.00
Common stock, par value	$ 1.00	$ 1.00
Common stock, shares issued	9,164us-gaap_CommonStockSharesIssued	9,164us-gaap_CommonStockSharesIssued
Treasury stock, shares	547us-gaap_TreasuryStockShares	593us-gaap_TreasuryStockShares

A valuation allowance for trade and other receivables due to an Entity within one year (or the normal operating cycle, whichever is longer) that are expected to be uncollectible.

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Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

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Face amount or stated value per share of preferred stock nonredeemable or redeemable solely at the option of the issuer.

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