Segment Information - Segment Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Jul. 31, 2014	Jul. 31, 2013
Segment Reporting Information [Line Items]
Revenues from external customers	$ 30,534	$ 32,003
Intersegment revenues
Earnings (loss) before income taxes	1,845	2,424
Corporate [Member]
Segment Reporting Information [Line Items]
Revenues from external customers
Intersegment revenues	(656)	(1,890)
Earnings (loss) before income taxes	(1,062)	(1,315)
Domestic Operations [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues from external customers	24,248	27,073
Intersegment revenues	124	1,404
Earnings (loss) before income taxes	2,203	3,182
International Operations [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues from external customers	6,286	4,930
Intersegment revenues	532	486
Earnings (loss) before income taxes	$ 704	$ 557

This element represents the income or loss from continuing operations attributable to the economic entity which may also be defined as revenue less expenses from ongoing operations, after income or loss from equity method investments, but before income taxes, extraordinary items, and noncontrolling interest.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 10

-Article 5

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- Definition

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Article 5

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- Definition

Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

+ References

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